Ruby.NET development has been moving ahead and Ruby.NET 0.9 is now released. Highlights of the release:
It includes substantial improvements to the previous version, including improved Ruby/.NET interoperability, .NET subtyping, creation of .NET delegates using Ruby blocks and support for visual design of Windows Forms applications within Visual Studio. We've also fixed lots of bugs and are close to getting Ruby on Rails to run successfully.Next to the more complete Ruby standard library, most of the new features improve interoperability of Ruby and .NET. Creating .NET delegates from Ruby blocks should make it easier to write event handling code with Ruby. This can be seen with another feature in Ruby.NET's Visual Studio integration, Ruby support for the Forms Designer. This means it's possible to build GUIs and use them from Ruby.NET code.
Most of Ruby's built in classes and modules have now been implemented completely. The notable exceptions are the Thread class and the Continuation class. Most Ruby language features are also now completely implemented (with tracing being a notable exception).
Supporting Visual Studio's GUI builder seems to be a popular feature in the .NET based Ruby tool space - SapphireSteel's Ruby in Steel IDE also recently showed a preview of a Visual Form Designer for IronRuby. It's also possible to use Windows Form GUIs from a regular Ruby interpreter (MRI) using SapphireSteel's .NET Ruby connector.