Announcing the Dynamic Language Runtime 0.91 Release

May 22, 2009 at 5:55 PM

Today we’re releasing version 0.91 of the Dynamic Language Runtime (DLR):

This release has several design cleanups and final calls for the bits we’re shipping in CLR 4.0. This release is also consistent with Visual Studio’s Beta1 release in that these sources (with namespace tweaks) were used for parts of CLR 4.0. Documents have all been updated, and there is a new walkthrough document for an example language implementation on the DLR. The language, Sympl, has a C# and an IronPython implementation in the source tree, along with some example code written in Sympl. There are many one-off examples for Expression Trees node types that are in the DLR source tree now.

The DLR Codeplex project is one-stop shopping for all the languages and samples the DLR team releases, and there are consistent releases on our individual language sites. For the IronPython release, go to
. The IronRuby release can be found at

If you want to read some documents without downloading sources or bits, go to

  • dlr-overview.doc
  • dlr-spec-hosting.doc
  • sites-binders-dyn-objs-spec.doc
  • library-authors-introduction.doc
  • expr-tree-spec.doc
  • sympl.doc

The DLR sources in this release are consistent with those in Visual Studio 2010 Beta1. They are from the end of March. Development has continued since then, and the latest sources are always available here:
. The same docs mentioned above are in the release zip file, and they describe the latest sources.


- The DLR Team