I followed the description under http://analyses.ishs.ulg.ac.be/logiciels/weft-qda.installation.debian.en.html and then
tried to start weft-qda.

I got:

ruby -rubygems weft_qda-1.9.0/weft-qda.rb
/var/lib/gems/1.8/gems/locale-2.0.4/lib/locale.rb:239:in `collect_candidates': undefined method `size' for nil:NilClass
(NoMethodError)
        from /var/lib/gems/1.8/gems/locale-2.0.4/lib/locale.rb:222:in `candidates'
        from /var/lib/gems/1.8/gems/gettext-2.0.4/lib/gettext/textdomain_manager.rb:79:in `each_textdomains'
        from /var/lib/gems/1.8/gems/gettext-2.0.4/lib/gettext/textdomain_manager.rb:102:in `translate_singluar_message'
        from /var/lib/gems/1.8/gems/gettext-2.0.4/lib/gettext.rb:130:in `_'
        from /home/andreas/weft_qda-1.9.0/lib/weft/wxgui/client.rb:277
        from /usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
        from /usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `require'
        from /home/andreas/weft_qda-1.9.0/lib/weft/wxgui.rb:56
        from /usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
        from /usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `require'
        from weft_qda-1.9.0/weft-qda.rb:44
/usr/lib/ruby/1.8/rubygems/custom_require.rb:31: [BUG] Segmentation fault
ruby 1.8.7 (2008-08-11 patchlevel 72) [i486-linux]

Aborted

I then tried 1.0.1

I get:

/var/lib/gems/1.8/bin/weft-qda.rb
PDFtotext Version 3 not found in path; PDF Filters will not be available
/usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require': no such file to load -- wxruby (LoadError)
        from /usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `require'
        from /var/lib/gems/1.8/gems/weft-qda-1.0.1/lib/weft/wxgui.rb:1
        from /usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `gem_original_require'
        from /usr/lib/ruby/1.8/rubygems/custom_require.rb:31:in `require'
        from /var/lib/gems/1.8/gems/weft-qda-1.0.1/./weft-qda.rb:43
        from /var/lib/gems/1.8/bin/weft-qda.rb:19:in `load'
        from /var/lib/gems/1.8/bin/weft-qda.rb:19