TextMate on OS X has long been the favored Rails editor, but the classic editors are still going strong. See VIM for Rails and Emacs for Rails.

For a full-on IDE, check out RadRails, RubyMine, or 3rd Rail.

Rails is blessed with multiple startups dedicated to helping you track and improve the performance of your applications: New Relic and Scout. Any high traffic Rails application should use one of these.

While Rails hosting is now common place, there's a handful of dedicated Rails hosting companies that have been around for a long time and supporting the community: Rails Machine, Joyent, Brightbox, Engine Yard, and Heroku. If you're just looking for a VPS, we recommend Slicehost or Linode.

Lots of Rails consultants stand ready to help develop your application or train your team. Koz from core works individually and we all like the teams from WyeWorks, entp, Thoughtbot, Pivotal Labs, Fingertips, Planet Argon and Phusion. You can find even more consultants at Working with Rails.

RailsConf is the official yearly Rails conference, but there are also a bunch of regularly regional ones too. See the complete list of upcoming conferences on the Ruby event calendar.