I have spent last two days (and few evenings before) playing with Rails and using Netbeans Ruby IDE. What a great experience ! Unlike before, it is so much easier to have really good debugger that allows put breakpoints not only into the Ruby code in controllers and model - but even into the RHTML view files !
Netbeans team works hard on improving the tool. With latest build - 2434, I have noticed great addition - Rails console. The IDE had IRB window even before, but the environment did not load the Rails context and would not recognize e.g. ActiveRecord. Now with latest build, everything works like charm.
Using Rails and coding in Ruby is real pleasure and the only pain-point was (compared to using Eclipse with Java or Visual Studio 2005 with C#) unavailability of a really good IDE. Yes - I tried RadRails and RDT plugin, but they still need lots of improvement and are not (yet) in the same league. Netbeans Ruby IDE is right now very likely best available free environment for Ruby and Rails environment. It allows work with both Ruby and JRuby with or without Rails - what more can you want ;-) ?
Thanks, Sun and the Netbeans team !