When the Dynamic Language Runtime was announced there were four languages under consideration, VB, Ruby, ECMAScript, and Python. While there has been no mention of DLR version of VB and ECMAScript in years, IronRuby and IronPython are about the celebrate major releases.
IronPython had its 1.0 release in September of 2006, three years after Jim Hugunin started the project. Jim Hugunin is also the creator of the Java version of Python, Jython. There are currently two release candidates for IronPython, version 2.6.1 for .NET 2.0 and their first for .NET 4.0.
In 2007 John Lam presented the first alpha release of IronRuby. Nearly three years later, IronRuby has announced their second 1.0 release candidate for .NET 2.0. There is also a version for .NET 4.0, but it is still just a preview.