The shipment of IronPython 1.0 this week marks a milestone for the long-running project, aimed at developing a Python implementation on Microsoft's .Net platform, and for developers' goal of expanding .Net support for dynamic programming languages.

Released through Microsoft's CodePlex shared-source portal, IronPython offers programmers a flexible, lightweight coding language. Its lead developer, Jim Hugunin, joined Microsoft to advance the project after gaining fame through his creation of Jython, a Java Python implementation.

Hugunin began work on IronPython with a contrary goal in mind: In the wake of online reports that Microsoft's Common Language Runtime (CLR) is inhospitable to dynamic languages, he decided to test the claims.

"My plan was to take a couple of weeks to build a prototype implementation of Python on the CLR and then to use that work to write a short, pithy article called, 'Why the CLR is a terrible platform for dynamic languages,' " Hugunin wrote in a blog post commemorating IronPython 1.0's release. "My plans quickly changed as I worked on the prototype because I found that Python could run extremely well on the CLR -- in many cases, noticeably faster than the C-based implementation."

Hugunin called IronPython the most complete and well-tested 1.0 release he's ever worked on. The software, which runs on .Net 2.0, carries a custom shared-source license that hasn't been submitted for Open Source Initiative (OSI) approval but allows for unlimited source-code copying and the creation of derivative works.