Scott Chacon talks about the technologies that power GitHub (Erlang, Redis,...), and the benefits of Git as a version control and as a storage system.Also: ShowOff, Scott's JS-based presentation tool.
Kevin Rutherford talks about the challenges of refactoring Ruby code, and his open source tool 'reek' which automates the discovery of certain code smells in Ruby code.
John Leach explains how Brightbox uses Virtualization in the data center and whether Virtualization causes performance problems. Also: a look at a few Unix tools and Linux features that Ruby developers might not know about.
Carl Lerche talks about the changes, design and new features in Rails 3. Also: the concepts and reasons behind Arel, the Rails 3 relational algebra library.