My company, LiveLogix, has just released (under the GNU GPL):
Logix - Multi-Language Programming for Python (0.3 alpha)
From the website:
Logix is more than a programming language. It is multi-language programming system. With Logix, each part of your program can be developed in a language that is finely tuned to the task.
Featuring a procedural macro facility, dynamic syntax extension, and multi-language parsing. A new operator, complete with syntax and semantics, can be added on-the-fly with a single line of code.
Tom Locke, LiveLogix.