I will focus on Ruby on Rails this one week or two …(server side of course)

get some links to remember:

http://haproxy.1wt.eu/

Rails Performance Testing Tools

http://blog.fiveruns.com/2008/10/30/benchmarking-rails

good articles to scaling the ruby apps.

http://poocs.net/2006/3/13/the-adventures-of-scaling-stage-1

http://poocs.net/articles/2006/03/20/the-adventures-of-scaling-stage-2

http://poocs.net/articles/2006/03/27/the-adventures-of-scaling-stage-3

http://poocs.net/articles/2006/04/03/the-adventures-of-scaling-stage-4

Memcached Integration in Rails

http://www.linuxjournal.com/article/10300