The Computer Language Benchmarks Game is a collection of 429 programs, consisting of 13 benchmark reimplemented across 33 programming languages. It is a fantastic resource if you are trying to compare programming languages quantitatively. Which, oddly, very few people seems to be interested in doing.
Writing a compiler in Ruby, bottom up
nice slides about ruby on rails and scaling.
"Adrian Holovaty, one of the creators of the Django framework for Python, and David Heinemeier Hansson, the creator of Ruby on Rails framework, answered questions about their work and the future of Web-application development." (check ftp.sickos.org)
sean kelly at nasa compares j2ee, rails, zope/plone, turbogears and django.
"Ruby Grundlagen — PDF zum Buch 'RapidWeb Development mit Ruby on Rails'"