NeverBlock: Instant Scaling For Your Rails Apps -
Rails Performance (Thin Vs.NeverBlock::Thin)
The scaling characteristics under heavy load were benchmarked, we did so with 500 and 1000 concurrent requests.
Thin scaling 
NeverBlock::Thin scaling 
Memory consumption was recorded for the different configurations
Memory Consumption (Thin Vs. NeverBlock::Thin) 
New Relic - Rails performance monitoring plugin
The Rails Documentation App - Rails-doc.org
Clean your configuration with configuration_manager
Community Engine | A Social Networking Plugin for Ruby on Rails
Dynamically created methods in Ruby -
Use def, avoid define_method
“Imagine trying to make a Rails project LSB compliant — your database.yaml file would need to be in /etc, your log directory would need to be in /var, and your actual code would need to be in /usr. There went all of your fancy Rails “convention over configuration”, and you’re suddenly fighting Rails instead of using it, and everyone you ask for help just tells you to “put it in vendor”.” — Puppet Blog: Development and More
flamefest: Twitter Said To Be Abandoning Ruby on Rails