Through the last week I have been implementing Range-minimum matching, so that regexp'es like /ruby+/ and /ru(by){42,}/ now works.

I have also fought some bugs with nested repeat patterns. It was quite difficult to figure out what exactly were causing problems. But I managed to figure it out :-)

You can fetch the package here:
http://rubyforge.org/download.php/200/regexp-engine-0.2.tar.gz