Ruby
Deploy:
Optimizing resource usage
http://weblog.textdrive.com/article/175/rails-optimizing-resource-usage
Scaling Rails
http://railslab.newrelic.com/scaling-rails
http://www.infoq.com/articles/gregg-pollack-scaling-rails
MySql driver deficiencies makes Mongrel and WEBrick to hang
http://railsforum.com/viewtopic.php?id=3038
http://www.mail-archive.com/rubyonrails-deployment@googlegroups.com/msg00133.html
About gems
CMS
This seems interesting as long as is multi-lingual by default, not as Radius: http://zenadmin.org/en
Reference guides
http://www.techotopia.com/index.php/Ruby_Essentials
No need to mention rail's API: http://api.rubyonrails.org/
Adhearsion, an Asterisk framework
RubyFringe talk: http://www.infoq.com/interviews/phillips-adhearson-voip
Ruby for SymbyanOS
Take a look at: https://developer.symbian.com/main/community/open_source_projects/ruby/index.jsp





