Microsoft has just released the first alpha of IronPython 2.0.
This version of IronPython is built on top of the new Dynamic Language Runtime (DLR) which is a shared runtime for dynamic languages on CLI. One of the goals of DLR is to allow different dynamic languages to share library code, so in theory and the future my IronPython code would be able to access code in a IronRuby gem. The DLR is distributed as part of the IronPython release and is implemented with two assemblies - Microsoft.Scripting.dll and Microsoft.Scripting.Vestigial.dll
The final release of IronPython 2.0 will support the language features added to Python 2.5.
Microsoft has changed the license for IronPython to the Microsoft Permissive License. Comparing this with the IronPython 1.1 license, the new license doesn't appear to add any restrictions.
If you have read my other blog posts about IronPython, you would have noticed that I am a fan of of Mono, the open source implementation of the CLI. Sadly IronPython 2.0 will not run with Mono 18.104.22.168, as calls to the DLR assemblies cause a seg fault. I am not sure what path the Mono developers will take in relation to supporting DLR with Mono. They could modify the mono runtime to work with the DLR assemblies but it is likely the DLR license may not allow this. If they implement the DLR API inside Mono with a Mono namespace like Mono.Scripting, then any dynamic language using DLR would need to be conditionally compiled dependant on CLI implementation. So I await with interest for an "offical" comment from Miguel de Icaza.