Rails 4 is coming along nicely with a ton of new stuff, but this major release would have not been possible without the help of some people whose contributions have been outstanding. We want to dedicate this post to them, to show our appreciation and recognition for their extraordinary work:
Arun Agrawal has been helping with some housekeeping tasks. He puts a lot of effort to remove warnings, fix broken builds, remove some unneeded code, and ensure Rails works well with JRuby.
Vijay Dev leads the docrails front. He reviews documentation patches, which is a lot of work, and cross-merges docrails and Rails master periodically.
Guillermo Iguaran is a regular active core contributor. Recently he has extracted old-style mass-assignment protection to the new protected_attributes gem, and is helping with the assets pipeline related projects.
Toshinori Kajihara (kennyj) helps to fix and give attention to Active Record issues, which are the most part of Rails open issues.
Steve Klabnik is working on Rails issues like crazy. I mean, GitHub notifications generated by his activity flood your inbox. Giving sensible feedback, dynamizeing threads, and closing issues. He has been key in halving the number of open issues.
Francesco Rodríguez has mainly contributed to the documentation, and also helps with tickets and code. Francesco has extracted page and action caching out to gems.
Piotr Sarnacki is an old-timer. Piotr helps constantly in the project and has done a remarkable work on Rails engines and Action Pack.
Prem Sichanugrist has been helping regularly since the Rails 3 days in many ways. He recently performed the daunting task of converting all Rails guides from Textile to Markdown.
Carlos Antonio da Silva is among the most prolific Rails committers. He contributes in all fronts, code, docs, issues, discussions, etc.
Andrew White has also been helping regularly for a couple of years or so. He is a solid contributor in several areas and in particular knows routing very well.