With Ruby 1.9.1, the first stable version of the 1.9 series has been released and will certainly be adopted by numerous Ruby programmers. Ruby 1.9 introduced many semantic changes and even new syntax, which IDEs need to be able to handle. We conducted a survey among the major Ruby IDEs to find out which ones are 1.9 capable and what their plans are.

Ruby in Steel

Huw Collingbourne from SapphireSteel Software answered:

[..] we have been pretty aggressive in supporting flavours of Ruby including JRuby the alphas of IronRuby. We are naturally keeping a close eye on the development of Ruby 1.9 as it migrates towards Ruby 2.0 and we will support this when our customers request us to. Currently our customers tell us that they are using Ruby 1.8x and we have not received requests for support of Ruby 1.9.

NetBeans

Erno Mononen from Sun:

Full Ruby 1.9 support is coming in the next release of NetBeans Ruby IDE. Currently there is some limited support for it - you can develop with Ruby 1.9 in the IDE, i.e. the IDE accepts it as a Ruby platform and there are even some 1.9 specific hints, but we haven't yet switched the parser to the latest JRuby that brings full 1.9 support. In addition, the debugger is not compatible with 1.9 (this is not really specific to NB since ruby-debug-base is not yet 1.9 ready).

RubyMine

Dmitry Jemerov from JetBrains:

At the moment RubyMine does not support Ruby 1.9. Our main focus at the moment is getting out a solid and stable RubyMine 1.0 release supporting Ruby 1.8. We plan to add Ruby 1.9 support in a subsequent version of RubyMine after 1.0 (most likely in Q2'2009).

RadRails

Chris Williams from Aptana:

We have upgraded the included JRuby to 1.1.6 in our upcoming release and they've started working towards 1.9 compatibility in both parsing and execution, so we'll be getting that as a result of their work. And of course users can point RDT/RadRails as a 1.9 install as the interpreter they want to use. We've also had in code checks/warnings related to deprecated syntax that will be changed or removed in Ruby 1.9 (to help developers avoid using syntax that won't work going forward). But I haven't had time to extensively test how we handle 1.9's new syntax changes with regard to syntax checking/error markers and I imagine we mark use of any new syntax introduced in 1.9 as a syntax error for now (and still only mark removed syntax from 1.8 to 1.9 as warnings, though the user can change the priority level to show as an error).

It seems that some IDEs are on their way providing Ruby 1.9 support. Are you already using 1.9? If not, is it because your IDE of choice lacks support for it?