edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/IronRuby.Tests/Driver.cs;C1597865
File: Driver.cs
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/IronRuby.Tests/Driver.cs;C1597865  (server)    2/26/2010 5:26 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/IronRuby.Tests/Driver.cs;RbHAPI
@@ -30,6 +30,7 @@
 using System.Text;
 using System.Globalization;
 using System.Threading;
+using Microsoft.Scripting.Hosting.Providers;
 
 namespace IronRuby.Tests {
     public class TestCase {
@@ -89,7 +90,7 @@
 
             _runtime = Ruby.CreateRuntime(runtimeSetup);
             _engine = Ruby.GetEngine(_runtime);
-            _context = Ruby.GetExecutionContext(_engine);
+            _context = (RubyContext)HostingHelpers.GetLanguageContext(_engine);
         }
     }
 
@@ -339,7 +340,7 @@
             int status = 0;
 
             if (_runTokenizerDriver) {
-                TokenizerTestDriver driver = new TokenizerTestDriver(Ruby.GetExecutionContext(Ruby.CreateRuntime()));
+                TokenizerTestDriver driver = new TokenizerTestDriver((RubyContext)HostingHelpers.GetLanguageContext(Ruby.CreateEngine()));
                 if (!driver.ParseArgs(args)) {
                     return -3;
                 }
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/IronRuby.Tests/RubyTests.cs;C1605253
File: RubyTests.cs
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/IronRuby.Tests/RubyTests.cs;C1605253  (server)    2/26/2010 5:31 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/IronRuby.Tests/RubyTests.cs;RbHAPI
@@ -415,6 +415,7 @@
                 RubyHosting2,
                 RubyHosting3,
                 RubyHosting4,
+                RubyHosting5,
                 RubyHosting_Scopes1,
                 CrossRuntime1,
                 CrossRuntime2,
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/IronRuby.Tests/Runtime/ConstantTests.cs;C1426166
File: ConstantTests.cs
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/IronRuby.Tests/Runtime/ConstantTests.cs;C1426166  (server)    2/26/2010 5:27 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/IronRuby.Tests/Runtime/ConstantTests.cs;RbHAPI
@@ -16,6 +16,8 @@
 using IronRuby.Builtins;
 using System;
 using System.IO;
+using Microsoft.Scripting.Hosting.Providers;
+using IronRuby.Runtime;
 namespace IronRuby.Tests {
 
     public partial class Tests {
@@ -628,7 +630,7 @@
 end
 C
 ");
-            Ruby.GetExecutionContext(engine2).DefineGlobalVariable("C", c); 
+            ((RubyContext)HostingHelpers.GetLanguageContext(engine2)).DefineGlobalVariable("C", c); 
 
             var m = engine2.Execute(@"
 module M
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/IronRuby.Tests/Runtime/HostingTests.cs;C1597865
File: HostingTests.cs
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/IronRuby.Tests/Runtime/HostingTests.cs;C1597865  (server)    2/26/2010 5:26 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/IronRuby.Tests/Runtime/HostingTests.cs;RbHAPI
@@ -283,7 +283,7 @@
             var searchPaths = Engine.GetSearchPaths();
             Assert(new List<string>(searchPaths)[searchPaths.Count - 1] == ".");
 
-            bool result = Engine.RequireRubyFile("fcntl");
+            bool result = Engine.RequireFile("fcntl");
             Assert(result == true);
 
             // built-in class:
@@ -323,6 +323,29 @@
 #endif
         }
 
+        [Options(NoRuntime = true)]
+        public void RubyHosting5() {
+            // app-domain creation:
+            if (_driver.PartialTrust) return;
+
+            AppDomain domain = AppDomain.CreateDomain("foo");
+
+            var rs = ScriptRuntimeSetup.ReadConfiguration();
+            LanguageSetup ls = rs.GetRubySetup();
+            Debug.Assert(ls.Names.IndexOf("IronRuby") != -1);
+
+            var newSetup = new ScriptRuntimeSetup();
+            newSetup.AddRubySetup((s) => {
+                s.Options["Compatibility"] = RubyCompatibility.Ruby19;
+                s.Options["LibraryPaths"] = ls.Options["LibraryPaths"];
+            });
+
+            ScriptRuntime runtime = ScriptRuntime.CreateRemote(domain, newSetup);
+            ScriptEngine engine = runtime.GetRubyEngine();
+            Assert(engine.RequireFile("fcntl") == true);
+            Assert(engine.Execute<bool>("Object.constants.include?(:Fcntl)") == true);
+        }
+
         public void RubyHosting_Scopes1() {
             TestOutput(@"
 engine = IronRuby.create_engine
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Libraries.LCA_RESTRICTED/Builtins/ArrayOps.cs;C1090806
File: ArrayOps.cs
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Libraries.LCA_RESTRICTED/Builtins/ArrayOps.cs;C1090806  (server)    2/22/2010 5:18 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Libraries.LCA_RESTRICTED/Builtins/ArrayOps.cs;RbHAPI
@@ -50,7 +50,6 @@
         // Reinitialization. Not called when a factory/non-default ctor is called.
         [RubyMethod("initialize", RubyMethodAttributes.PrivateInstance)]
         public static RubyArray/*!*/ Reinitialize(RubyContext/*!*/ context, RubyArray/*!*/ self) {
-            RubyUtils.RequiresNotFrozen(context, self);
             self.Clear();
             return self;
         }
@@ -79,7 +78,6 @@
             BlockParam block, RubyArray/*!*/ self, [NotNull]object/*!*/ arrayOrSize) {
 
             var context = toAryToInt.Context;
-            RubyUtils.RequiresNotFrozen(context, self);
 
             var site = toAryToInt.GetSite(CompositeConversionAction.Make(context, CompositeConversion.ToAryToInt));
             var union = site.Target(site, arrayOrSize);
@@ -148,7 +146,6 @@
         // Reinitialization. Not called when a factory/non-default ctor is called.
         [RubyMethod("initialize", RubyMethodAttributes.PrivateInstance)]
         public static RubyArray/*!*/ ReinitializeByRepeatedValue(RubyContext/*!*/ context, RubyArray/*!*/ self, [DefaultProtocol]int size, object value) {
-            RubyUtils.RequiresNotFrozen(context, self);
             if (size < 0) {
                 throw RubyExceptions.CreateArgumentError("negative array size");
             }
@@ -251,7 +248,6 @@
 
             breakResult = null;
             var context = comparisonStorage.Context;
-            RubyUtils.RequiresNotFrozen(context, self);
 
             // TODO: this does more comparisons (and in a different order) than
             // Ruby's sort. Also, control flow won't work because List<T>.Sort wraps
@@ -298,7 +294,6 @@
 
         [RubyMethod("reverse!")]
         public static RubyArray/*!*/ InPlaceReverse(RubyContext/*!*/ context, RubyArray/*!*/ self) {
-            RubyUtils.RequiresNotFrozen(context, self);
             self.Reverse();
             return self;
         }
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Libraries.LCA_RESTRICTED/Builtins/HashOps.cs;C1561136
File: HashOps.cs
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Libraries.LCA_RESTRICTED/Builtins/HashOps.cs;C1561136  (server)    2/22/2010 5:22 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Libraries.LCA_RESTRICTED/Builtins/HashOps.cs;RbHAPI
@@ -108,8 +108,7 @@
 
         [RubyMethod("initialize_copy", RubyMethodAttributes.PrivateInstance)]
         public static Hash/*!*/ InitializeCopy(RubyContext/*!*/ context, Hash/*!*/ self, [NotNull]Hash/*!*/ source) {
-            RubyUtils.RequiresNotFrozen(context, self);
-
+            self.Mutate();
             self.DefaultProc = source.DefaultProc;
             self.DefaultValue = source.DefaultValue;
             IDictionaryOps.ReplaceData(self, source);
@@ -146,7 +145,7 @@
 
         [RubyMethod("default=")]
         public static object SetDefaultValue(RubyContext/*!*/ context, Hash/*!*/ self, object value) {
-            RubyUtils.RequiresNotFrozen(context, self);
+            self.Mutate();
             self.DefaultProc = null;
             return self.DefaultValue = value;
         }
@@ -188,8 +187,8 @@
                 return self;
             }
 
-            RubyUtils.RequiresNotFrozen(context, self);
-
+            self.Mutate();
+            
             Hash otherHash = other as Hash;
             if (otherHash != null) {
                 self.DefaultValue = otherHash.DefaultValue;
@@ -200,8 +199,8 @@
 
         [RubyMethod("shift")]
         public static object Shift(CallSiteStorage<Func<CallSite, Hash, object, object>>/*!*/ storage, Hash/*!*/ self) {
-            RubyUtils.RequiresNotFrozen(storage.Context, self);
-
+            self.Mutate();
+            
             if (self.Count == 0) {
                 var site = storage.GetCallSite("default", 1);
                 return site.Target(site, self, null);
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Libraries.LCA_RESTRICTED/Extensions/IDictionaryOps.cs;C1561136
File: IDictionaryOps.cs
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Libraries.LCA_RESTRICTED/Extensions/IDictionaryOps.cs;C1561136  (server)    2/22/2010 5:23 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Libraries.LCA_RESTRICTED/Extensions/IDictionaryOps.cs;RbHAPI
@@ -455,7 +455,7 @@
 
         [RubyMethod("replace")]
         public static Hash/*!*/ Replace(RubyContext/*!*/ context, Hash/*!*/ self, [DefaultProtocol, NotNull]IDictionary<object, object>/*!*/ other) {
-            RubyUtils.RequiresNotFrozen(context, self);
+            self.Mutate();
             return IDictionaryOps.ReplaceData(self, other);
         }
 
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Ruby.Build.csproj;C1597865
File: Ruby.Build.csproj
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Ruby.Build.csproj;C1597865  (server)    2/26/2010 6:01 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Ruby.Build.csproj;RbHAPI
@@ -283,6 +283,7 @@
       <!--                           -->
       <Compile Include="Hosting\RubyCommandLine.cs" />
       <Compile Include="Hosting\RubyOptionsParser.cs" />
+      <Compile Include="Hosting\RubyService.cs" />
     </ItemGroup>
     <ItemGroup>
       <!--                              -->
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Ruby.cs;C1221149
File: Ruby.cs
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Ruby.cs;C1221149  (server)    2/26/2010 4:06 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Ruby.cs;RbHAPI
@@ -23,6 +23,7 @@
 using Microsoft.Scripting.Runtime;
 using IronRuby.Runtime;
 using IronRuby.Builtins;
+using IronRuby.Hosting;
 using System.ComponentModel;
 using System;
 using System.Collections;
@@ -35,35 +36,53 @@
 #endif
 
 namespace IronRuby {
-    
+    /// <summary>
+    /// Implements IronRuby hosting APIs that enable embedding IronRuby in .NET application.
+    /// </summary>
+    /// <remarks>
+    /// This class provides convenience APIs for applications that host Ruby language in a specific way.
+    /// Use Dynamic Language Runtime (DLR) Hosting API from <see cref="Microsoft.Scripting.Hosting"/> namespace to implement language agnostic host, i.e.
+    /// a host that works with any present and future DLR based language.
+    /// </remarks>
     public static class Ruby {
         /// <summary>
         /// Creates a new script runtime configured using .NET configuration files.
-        /// If the .NET configuration doesn't include IronRuby a default IronRuby configuration is added.
+        /// If the .NET configuration doesn't include IronRuby record a default IronRuby configuration is added.
         /// </summary>
+        /// <returns>A runtime that is capable of running IronRuby scripts and scripts of any other language specified in the .NET configuration files.</returns>
         public static ScriptRuntime/*!*/ CreateRuntime() {
             var setup = ScriptRuntimeSetup.ReadConfiguration();
             setup.AddRubySetup();
             return new ScriptRuntime(setup);
         }
 
+        /// <summary>
+        /// Creates a runtime given a runtime setup.
+        /// </summary>
+        /// <param name="setup">The setup to use to configure the runtime. This contains all information that's needed for the runtime initialization.</param>
+        /// <returns>A runtime that is capable of running scripts of languages listed in <paramref name="setup"/>.</returns>
         public static ScriptRuntime/*!*/ CreateRuntime(ScriptRuntimeSetup/*!*/ setup) {
             return new ScriptRuntime(setup);
         }
 
         /// <summary>
-        /// Creates a new script runtime and returns its IronRuby engine.
+        /// Creates a new script runtime and returns its IronRuby engine configured using .NET configuration files.
         /// </summary>
+        /// <returns>A new IronRuby engine.</returns>
+        /// <remarks>Creates a runtime using <see cref="CreateRuntime()"/> method.</remarks>
         public static ScriptEngine/*!*/ CreateEngine() {
             return GetEngine(CreateRuntime());
         }
 
         /// <summary>
-        /// Creates a new script runtime and returns its IronRuby engine configured using <paramref name="rubySetup"/>.
+        /// Creates a new script runtime and returns its IronRuby engine configured configured using .NET configuration files.
         /// </summary>
-        /// <remarks>
-        /// If the configuration loaded from .config files already contains 
-        /// </remarks>
+        /// <param name="setupInitializer">
+        /// A delegate that receives an instance of IronRuby's <see cref="LanguageSetup"/> loaded from the .NET configuration 
+        /// and can set its properties before it is used for runtime configuration. 
+        /// If no IronRuby setup information is found in the .NET configuration a default one is created and passed to the initializer.
+        /// </param>
+        /// <returns>A new IronRuby engine.</returns>
         public static ScriptEngine/*!*/ CreateEngine(Action<LanguageSetup/*!*/>/*!*/ setupInitializer) {
             ContractUtils.RequiresNotNull(setupInitializer, "setupInitializer");
 
@@ -81,6 +100,10 @@
         /// <summary>
         /// Creates IronRuby setup with default language names and file extensions.
         /// </summary>
+        /// <returns>The IronRuby setup object.</returns>
+        /// <remarks>
+        /// The setup options can be modified before used for a script runtime creation.
+        /// </remarks>
         public static LanguageSetup/*!*/ CreateRubySetup() {
             return new LanguageSetup(
                 typeof(RubyContext).AssemblyQualifiedName,
@@ -90,6 +113,14 @@
             );
         }
 
+        /// <summary>
+        /// Creates a default IronRuby setup and passes it to the given delegate for initialization.
+        /// </summary>
+        /// <param name="initializer">
+        /// A delegate that receives a fresh instance of IronRuby's <see cref="LanguageSetup"/> 
+        /// and can set its properties before it is used for runtime configuration. 
+        /// </param>
+        /// <returns>The IronRuby setup object initialized by <paramref name="initializer"/>.</returns>
         public static LanguageSetup/*!*/ CreateRubySetup(Action<LanguageSetup/*!*/>/*!*/ initializer) {
             ContractUtils.RequiresNotNull(initializer, "initializer");
 
@@ -98,49 +129,20 @@
             return setup;
         }
 
+        /// <summary>
+        /// Retrieves an IronRuby engine from a given script runtime.
+        /// </summary>
+        /// <param name="runtime">The runtime to get the engine from.</param>
+        /// <returns>An IronRuby engine from the specified runtime.</returns>
+        /// <exception cref="ArgumentException">
+        /// The <paramref name="runtime"/> is not set up to run IronRuby. 
+        /// The <see cref="ScriptRuntimeSetup"/> doesn't contain IronRuby's <see cref="ScriptLanguageSetup"/>.
+        /// </exception>
         public static ScriptEngine/*!*/ GetEngine(ScriptRuntime/*!*/ runtime) {
             ContractUtils.RequiresNotNull(runtime, "runtime");
             return runtime.GetEngineByTypeName(typeof(RubyContext).AssemblyQualifiedName);
         }
 
-        public static bool RequireFile(ScriptEngine/*!*/ engine, string/*!*/ path) {
-            ContractUtils.RequiresNotNull(engine, "engine");
-            ContractUtils.RequiresNotNull(path, "path");
-
-            return HostingHelpers.CallEngine<KeyValuePair<string, Scope>, bool>(engine, RequireFile, 
-                new KeyValuePair<string, Scope>(path, null));
-        }
-
-        public static bool RequireFile(ScriptEngine/*!*/ engine, string/*!*/ path, ScriptScope/*!*/ scope) {
-            ContractUtils.RequiresNotNull(engine, "engine");
-            ContractUtils.RequiresNotNull(path, "path");
-            ContractUtils.RequiresNotNull(scope, "scope");
-
-            return HostingHelpers.CallEngine<KeyValuePair<string, Scope>, bool>(engine, RequireFile, 
-                new KeyValuePair<string, Scope>(path, HostingHelpers.GetScope(scope)));
-        }
-
-        internal static bool RequireFile(LanguageContext/*!*/ context, KeyValuePair<string, Scope> pathAndScope) {
-            var rc = (RubyContext)context;
-            return rc.Loader.LoadFile(pathAndScope.Value, null, MutableString.Create(pathAndScope.Key, RubyEncoding.UTF8), LoadFlags.Require);
-        }
-
-        // TODO:
-        public static RubyContext/*!*/ GetExecutionContext(ScriptEngine/*!*/ engine) {
-            ContractUtils.RequiresNotNull(engine, "engine");
-            var context = HostingHelpers.GetLanguageContext(engine) as RubyContext;
-            if (context == null) {
-                throw new InvalidOperationException("Given engine is not a Ruby engine");
-            }
-            return context;
-        }
-
-        // TODO:
-        public static RubyContext/*!*/ GetExecutionContext(ScriptRuntime/*!*/ runtime) {
-            ContractUtils.RequiresNotNull(runtime, "runtime");
-            return GetExecutionContext(GetEngine(runtime));
-        }
-
         internal static int IndexOfRubySetup(ScriptRuntimeSetup/*!*/ runtimeSetup) {
             for (int i = 0; i < runtimeSetup.LanguageSetups.Count; i++) {
                 var langSetup = runtimeSetup.LanguageSetups[i];
@@ -154,23 +156,78 @@
 
     [EditorBrowsable(EditorBrowsableState.Never)]
     public static class RubyHostingExtensions {
-        public static bool RequireRubyFile(this ScriptEngine/*!*/ engine, string/*!*/ path) {
-            return Ruby.RequireFile(engine, path);
+        /// <summary>
+        /// Loads a given script file using the semantics of Kernel#require method.
+        /// </summary>
+        /// <param name="engine">The Ruby engine.</param>
+        /// <param name="path">The path to the file to load.</param>
+        /// <returns>Whether the file has already been required.</returns>
+        /// <remarks>
+        /// If a relative path is given the current search paths are used to locate the script file.
+        /// The current search paths could be read and modified via <see cref="ScriptEngine.GetSearchPaths"/> and <see cref="ScriptEngine.SetSearchPaths"/>,
+        /// respectively.
+        /// </remarks>
+        public static bool RequireFile(this ScriptEngine/*!*/ engine, string/*!*/ path) {
+            return engine.GetService<RubyService>(engine).RequireFile(path);
+        }
+
+        /// <summary>
+        /// Loads a given script file using the semantics of Kernel#require method.
+        /// The script is executed within the context of a given <see cref="ScriptScope"/>.
+        /// </summary>
+        /// <param name="engine">The Ruby engine.</param>
+        /// <param name="path">The path to the file to load.</param>
+        /// <param name="scope">The scope to use for the script execution.</param>
+        /// <returns>Whether the file has already been required.</returns>
+        /// <remarks>
+        /// If a relative path is given the current search paths are used to locate the script file.
+        /// The current search paths could be read and modified via <see cref="ScriptEngine.GetSearchPaths"/> and <see cref="ScriptEngine.SetSearchPaths"/>,
+        /// respectively.
+        /// </remarks>
+        public static bool RequireFile(this ScriptEngine/*!*/ engine, string/*!*/ path, ScriptScope/*!*/ scope) {
+            return engine.GetService<RubyService>(engine).RequireFile(path, scope);
         }
 
+        /// <summary>
+        /// Retrieves an IronRuby engine from a given script runtime.
+        /// </summary>
+        /// <param name="runtime">The runtime to get the engine from.</param>
+        /// <returns>An IronRuby engine from the specified runtime.</returns>
+        /// <exception cref="ArgumentException">
+        /// The <paramref name="runtime"/> is not set up to run IronRuby. 
+        /// The <see cref="ScriptRuntimeSetup"/> doesn't contain IronRuby's <see cref="ScriptLanguageSetup"/>.
+        /// </exception>
         public static ScriptEngine/*!*/ GetRubyEngine(this ScriptRuntime/*!*/ runtime) {
             return Ruby.GetEngine(runtime);
         }
 
+        /// <summary>
+        /// Retrieves IronRuby setup from the runtime setup.
+        /// </summary>
+        /// <param name="runtimeSetup">Runtime setup.</param>
+        /// <returns>IronRuby setup or <c>null</c> if the runtime setup doesn't contain one.</returns>
+        public static LanguageSetup GetRubySetup(this ScriptRuntimeSetup/*!*/ runtimeSetup) {
+            int index = Ruby.IndexOfRubySetup(runtimeSetup);
+            return (index != -1) ? runtimeSetup.LanguageSetups[index] : null;
+        }
+
+        /// <summary>
+        /// Adds a new IronRuby setup into the runtime setup unless already included.
+        /// </summary>
+        /// <param name="runtimeSetup">The <see cref="ScriptRuntimeSetup"/> to update.</param>
+        /// <returns>The new setup or the existing setup object.</returns>
         public static LanguageSetup/*!*/ AddRubySetup(this ScriptRuntimeSetup/*!*/ runtimeSetup) {
             return AddRubySetup(runtimeSetup, null);
         }
 
         /// <summary>
-        /// Adds a new Ruby setup into the given runtime setup unless Ruby setup is already there.
-        /// Returns the newly created setup or the existing one.
-        /// If non-null <paramref name="newSetupInitializer"/> is given and a new setup is created runs the initializer on the new setup instance.
+        /// Adds a new IronRuby setup into the given runtime setup unless already included.
         /// </summary>
+        /// <param name="runtimeSetup">The <see cref="ScriptRuntimeSetup"/> to update.</param>
+        /// <param name="newSetupInitializer">
+        /// If not <c>null</c>, <paramref name="newSetupInitializer"/> is used to initialize the new IronRuby <see cref="LanguageSetup"/>.
+        /// </param>
+        /// <returns>The new setup initialized by <paramref name="newSetupInitializer"/> or the existing setup object.</returns>
         public static LanguageSetup/*!*/ AddRubySetup(this ScriptRuntimeSetup/*!*/ runtimeSetup, Action<LanguageSetup/*!*/> newSetupInitializer) {
             ContractUtils.RequiresNotNull(runtimeSetup, "runtimeSetup");
             
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Ruby.csproj;C1597865
File: Ruby.csproj
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Ruby.csproj;C1597865  (server)    2/26/2010 4:52 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Ruby.csproj;RbHAPI
@@ -255,6 +255,7 @@
     <Compile Include="Compiler\Errors.cs" />
     <Compile Include="Compiler\Generation\IRubyType.cs" />
     <Compile Include="Compiler\Parser\ParserStack.cs" />
+    <Compile Include="Hosting\RubyService.cs" />
     <Compile Include="Runtime\BinaryContentProvider.cs" />
     <Compile Include="Runtime\CallSiteStorages.cs" />
     <Compile Include="Runtime\Calls\RubyScopeMethodMissingInfo.cs" />
@@ -469,4 +470,4 @@
   </Target>
   <Target Name="AfterBuild">
   </Target>
-</Project>
+</Project>
\ No newline at end of file
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Builtins/Hash.cs;C966724
File: Hash.cs
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Builtins/Hash.cs;C966724  (server)    2/22/2010 5:20 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Builtins/Hash.cs;RbHAPI
@@ -24,13 +24,17 @@
     /// Dictionary inherits from Object, mixes in Enumerable.
     /// Ruby hash is a Dictionary{object, object}, but it adds default value/proc
     /// </summary>
-    public partial class Hash : Dictionary<object, object>, IDuplicable {
+    public partial class Hash : Dictionary<object, object>, IRubyObjectState, IDuplicable {
 
         // The default value can be a Proc that we should *return*, and that is different
         // from the default value being a Proc that we should *call*, hence two variables
         private Proc _defaultProc;
         private object _defaultValue;
 
+        private uint _flags;
+        private const uint IsFrozenFlag = 1;
+        private const uint IsTaintedFlag = 2;
+
         public Proc DefaultProc { get { return _defaultProc; } set { _defaultProc = value; } }
         public object DefaultValue { get { return _defaultValue; } set { _defaultValue = value; } }
 
@@ -91,5 +95,40 @@
         }
 
         #endregion
+
+        #region Flags
+
+        public void Mutate() {
+            if ((_flags & IsFrozenFlag) != 0) {
+                throw RubyExceptions.CreateObjectFrozenError();
+            }
+        }
+
+        public bool IsTainted {
+            get {
+                return (_flags & IsTaintedFlag) != 0;
+            }
+            set {
+                Mutate();
+                _flags = (_flags & ~IsTaintedFlag) | (value ? IsTaintedFlag : 0);
+            }
+        }
+
+        public bool IsFrozen {
+            get {
+                return (_flags & IsFrozenFlag) != 0;
+            }
+        }
+
+        void IRubyObjectState.Freeze() {
+            Freeze();
+        }
+
+        public Hash/*!*/ Freeze() {
+            _flags |= IsFrozenFlag;
+            return this;
+        }
+
+        #endregion
     }
 }
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Builtins/RubyArray.cs;C1602122
File: RubyArray.cs
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Builtins/RubyArray.cs;C1602122  (server)    2/22/2010 5:17 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Builtins/RubyArray.cs;RbHAPI
@@ -136,7 +136,7 @@
 
         #endregion
 
-        #region Versioning, Flags
+        #region Flags
 
         private void Mutate() {
             if ((_flags & IsFrozenFlag) != 0) {
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Builtins/Subclasses.Generated.cs;C1597865
File: Subclasses.Generated.cs
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Builtins/Subclasses.Generated.cs;C1597865  (server)    2/22/2010 5:24 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Builtins/Subclasses.Generated.cs;RbHAPI
@@ -20,7 +20,7 @@
 
 namespace IronRuby.Builtins {
 #if GENERATOR
-    Stateless = ['Proc', 'Range', 'RubyRegex', 'RubyIO']
+    Stateless = ['Range', 'RubyRegex', 'RubyIO']
 
     def generate
       Stateless.each do |cls| 
@@ -33,10 +33,10 @@
       @class
     end
 #else
-    public partial class /*$Class{*/Hash/*}*/ {
+    public partial class /*$Class{*/Proc/*}*/ {
         [DebuggerTypeProxy(typeof(RubyObjectDebugView))]
         [DebuggerDisplay(RubyObject.DebuggerDisplayValue, Type = RubyObject.DebuggerDisplayType)]
-        public sealed partial class Subclass : /*$Class{*/Hash/*}*/, IRubyObject {
+        public sealed partial class Subclass : /*$Class{*/Proc/*}*/, IRubyObject {
             private RubyInstanceData _instanceData;
             private RubyClass/*!*/ _immediateClass;
             
@@ -89,10 +89,10 @@
 #endif
 #region Generated by Subclasses.Generator.rb
 
-    public partial class Proc {
+    public partial class Range {
         [DebuggerTypeProxy(typeof(RubyObjectDebugView))]
         [DebuggerDisplay(RubyObject.DebuggerDisplayValue, Type = RubyObject.DebuggerDisplayType)]
-        public sealed partial class Subclass : Proc, IRubyObject {
+        public sealed partial class Subclass : Range, IRubyObject {
             private RubyInstanceData _instanceData;
             private RubyClass/*!*/ _immediateClass;
             
@@ -142,10 +142,10 @@
             }
         }
     }
-    public partial class Range {
+    public partial class RubyRegex {
         [DebuggerTypeProxy(typeof(RubyObjectDebugView))]
         [DebuggerDisplay(RubyObject.DebuggerDisplayValue, Type = RubyObject.DebuggerDisplayType)]
-        public sealed partial class Subclass : Range, IRubyObject {
+        public sealed partial class Subclass : RubyRegex, IRubyObject {
             private RubyInstanceData _instanceData;
             private RubyClass/*!*/ _immediateClass;
             
@@ -195,10 +195,10 @@
             }
         }
     }
-    public partial class RubyRegex {
+    public partial class RubyIO {
         [DebuggerTypeProxy(typeof(RubyObjectDebugView))]
         [DebuggerDisplay(RubyObject.DebuggerDisplayValue, Type = RubyObject.DebuggerDisplayType)]
-        public sealed partial class Subclass : RubyRegex, IRubyObject {
+        public sealed partial class Subclass : RubyIO, IRubyObject {
             private RubyInstanceData _instanceData;
             private RubyClass/*!*/ _immediateClass;
             
@@ -248,10 +248,27 @@
             }
         }
     }
-    public partial class RubyIO {
+
+#endregion
+
+#if GENERATOR
+    Stateful = ['RubyArray', 'Hash', 'MatchData']
+
+    def generate
+      Stateful.each do |cls| 
+        @class = cls
+        super 
+      end
+    end
+
+    def Class *a
+      @class
+    end
+#else
+    public partial class /*$Class{*/MutableString/*}*/ {
         [DebuggerTypeProxy(typeof(RubyObjectDebugView))]
         [DebuggerDisplay(RubyObject.DebuggerDisplayValue, Type = RubyObject.DebuggerDisplayType)]
-        public sealed partial class Subclass : RubyIO, IRubyObject {
+        public sealed partial class Subclass : /*$Class{*/MutableString/*}*/, IRubyObject {
             private RubyInstanceData _instanceData;
             private RubyClass/*!*/ _immediateClass;
             
@@ -275,19 +292,6 @@
                 return _instanceData;
             }
 
-            public bool IsFrozen {
-                get { return _instanceData != null && _instanceData.Frozen; }
-            }
-
-            public bool IsTainted {
-                get { return _instanceData != null && _instanceData.Tainted; }
-                set { GetInstanceData().Tainted = value; }
-            }
-
-            public void Freeze() {
-                GetInstanceData().Freeze();
-            }
-
             public int BaseGetHashCode() {
                 return base.GetHashCode();
             }
@@ -301,27 +305,13 @@
             }
         }
     }
+#endif
+#region Generated by Subclasses.Generator.rb
 
-#endregion
-
-#if GENERATOR
-    Stateful = ['RubyArray', 'MatchData']
-
-    def generate
-      Stateful.each do |cls| 
-        @class = cls
-        super 
-      end
-    end
-
-    def Class *a
-      @class
-    end
-#else
-    public partial class /*$Class{*/MutableString/*}*/ {
+    public partial class RubyArray {
         [DebuggerTypeProxy(typeof(RubyObjectDebugView))]
         [DebuggerDisplay(RubyObject.DebuggerDisplayValue, Type = RubyObject.DebuggerDisplayType)]
-        public sealed partial class Subclass : /*$Class{*/MutableString/*}*/, IRubyObject {
+        public sealed partial class Subclass : RubyArray, IRubyObject {
             private RubyInstanceData _instanceData;
             private RubyClass/*!*/ _immediateClass;
             
@@ -358,13 +348,10 @@
             }
         }
     }
-#endif
-#region Generated by Subclasses.Generator.rb
-
-    public partial class RubyArray {
+    public partial class Hash {
         [DebuggerTypeProxy(typeof(RubyObjectDebugView))]
         [DebuggerDisplay(RubyObject.DebuggerDisplayValue, Type = RubyObject.DebuggerDisplayType)]
-        public sealed partial class Subclass : RubyArray, IRubyObject {
+        public sealed partial class Subclass : Hash, IRubyObject {
             private RubyInstanceData _instanceData;
             private RubyClass/*!*/ _immediateClass;
             
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Hosting/RubyCommandLine.cs;C1496258
File: RubyCommandLine.cs
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Hosting/RubyCommandLine.cs;C1496258  (server)    2/26/2010 5:17 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Hosting/RubyCommandLine.cs;RbHAPI
@@ -121,7 +121,7 @@
 
         protected override void UnhandledException(Exception e) {
             // Kernel#at_exit can access $!. So we need to publish the uncaught exception
-            Ruby.GetExecutionContext(Engine).CurrentException = e;
+            ((RubyContext)Language).CurrentException = e;
 
             base.UnhandledException(e);
         }
===================================================================
add: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Hosting/RubyService.cs
File: RubyService.cs
===================================================================
--- [no source file]
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Hosting/RubyService.cs;RbHAPI
@@ -1,0 +1,86 @@
+/* ****************************************************************************
+ *
+ * Copyright (c) Microsoft Corporation. 
+ *
+ * This source code is subject to terms and conditions of the Microsoft Public License. A 
+ * copy of the license can be found in the License.html file at the root of this distribution. If 
+ * you cannot locate the  Microsoft Public License, please send an email to 
+ * dlr@microsoft.com. By using this source code in any fashion, you are agreeing to be bound 
+ * by the terms of the Microsoft Public License.
+ *
+ * You must not remove this notice, or any other, from this software.
+ *
+ *
+ * ***************************************************************************/
+
+using System;
+using System.Security.Permissions;
+using IronRuby.Runtime;
+using Microsoft.Scripting.Hosting;
+using Microsoft.Scripting.Hosting.Providers;
+using Microsoft.Scripting.Runtime;
+using Microsoft.Scripting.Utils;
+
+namespace IronRuby.Hosting {
+    public sealed class RubyService
+#if !SILVERLIGHT
+ : MarshalByRefObject
+#endif
+ {
+        private readonly ScriptEngine/*!*/ _engine;
+        private readonly RubyContext/*!*/ _context;
+
+        internal RubyService(RubyContext/*!*/ context, ScriptEngine/*!*/ engine) {
+            Assert.NotNull(context, engine);
+            _context = context;
+            _engine = engine;
+        }
+
+        /// <summary>
+        /// Loads a given script file using the semantics of Kernel#require method.
+        /// </summary>
+        /// <param name="engine">The Ruby engine.</param>
+        /// <param name="path">The path to the file to load.</param>
+        /// <returns>Whether the file has already been required.</returns>
+        /// <remarks>
+        /// If a relative path is given the current search paths are used to locate the script file.
+        /// The current search paths could be read and modified via <see cref="ScriptEngine.GetSearchPaths"/> and <see cref="ScriptEngine.SetSearchPaths"/>,
+        /// respectively.
+        /// </remarks>
+        public bool RequireFile(string/*!*/ path) {
+            ContractUtils.RequiresNotNull(path, "path");
+            return RequireFile(path, (Scope)null);
+        }
+
+        /// <summary>
+        /// Loads a given script file using the semantics of Kernel#require method.
+        /// The script is executed within the context of a given <see cref="ScriptScope"/>.
+        /// </summary>
+        /// <param name="engine">The Ruby engine.</param>
+        /// <param name="path">The path to the file to load.</param>
+        /// <param name="scope">The scope to use for the script execution.</param>
+        /// <returns>Whether the file has already been required.</returns>
+        /// <remarks>
+        /// If a relative path is given the current search paths are used to locate the script file.
+        /// The current search paths could be read and modified via <see cref="ScriptEngine.GetSearchPaths"/> and <see cref="ScriptEngine.SetSearchPaths"/>,
+        /// respectively.
+        /// </remarks>
+        public bool RequireFile(string/*!*/ path, ScriptScope/*!*/ scope) {
+            ContractUtils.RequiresNotNull(path, "path");
+            ContractUtils.RequiresNotNull(scope, "scope");
+            return RequireFile(path, HostingHelpers.GetScope(scope));
+        }
+
+        private bool RequireFile(string/*!*/ path, Scope scope) {
+            return _context.Loader.LoadFile(scope, null, _context.EncodePath(path), LoadFlags.Require);
+        }
+
+#if !SILVERLIGHT
+        [SecurityPermission(SecurityAction.LinkDemand, Flags = SecurityPermissionFlag.Infrastructure)]
+        public override object InitializeLifetimeService() {
+            // track the engines lifetime
+            return _engine.InitializeLifetimeService();
+        }
+#endif
+    }
+}
===================================================================
edit: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Runtime/RubyContext.cs;C1599184
File: RubyContext.cs
===================================================================
--- $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Runtime/RubyContext.cs;C1599184  (server)    2/26/2010 5:18 PM
+++ Shelved Change: $/Dev10/feature/vs_langs01_s/Merlin/Main/Languages/Ruby/Ruby/Runtime/RubyContext.cs;RbHAPI
@@ -33,6 +33,7 @@
 using IronRuby.Compiler;
 using IronRuby.Compiler.Ast;
 using IronRuby.Compiler.Generation;
+using IronRuby.Hosting;
 using IronRuby.Runtime.Calls;
 using IronRuby.Runtime.Conversions;
 using Microsoft.Scripting;
@@ -41,9 +42,6 @@
 using Microsoft.Scripting.Utils;
 
 namespace IronRuby.Runtime {
-    /// <summary>
-    /// An isolation context: could be per thread/request or shared accross certain threads.
-    /// </summary>
     [ReflectionCached]
     public sealed class RubyContext : LanguageContext {
         internal static readonly Guid RubyLanguageGuid = new Guid("F03C4640-DABA-473f-96F1-391400714DAB");
@@ -107,6 +105,7 @@
         private readonly RubyMetaBinderFactory/*!*/ _metaBinderFactory;
         private readonly RubyBinder _binder;
         private DynamicDelegateCreator _delegateCreator;
+        private RubyService _rubyService;
 
         #region Global Variables (thread-safe access)
 
@@ -2678,6 +2677,10 @@
         #region Language Context Overrides
 
         public override TService GetService<TService>(params object[] args) {
+            if (typeof(TService) == typeof(RubyService)) {
+                return (TService)(object)(_rubyService ?? (_rubyService = new RubyService(this, (Microsoft.Scripting.Hosting.ScriptEngine)args[0])));
+            } 
+            
             if (typeof(TService) == typeof(TokenizerService)) {
                 return (TService)(object)new Tokenizer();
             }
===================================================================