Ace is a programming language with a modularly extensible static type system. It borrows Python's syntax directly and uses Python as a compile-time metalanguage. That is, to put it more simply, Ace is embedded within Python.
Ace is still under development. If you'd like to help, get in touch with Cyrus (see below). If you'd like to be informed when Ace is more ready for you, join the ace-announce mailing list:
The most well-developed set of extensions included with Ace implement the entirety of the OpenCL kernel programming language (and include a convenient wrapper around the host API as well, although its use is optional).
Ace is the best way to write low-level GPU kernels in OpenCL today, no contest.
A not-quite-complete set of extensions that implement the C99 programming language are also included.
Some functional programming constructs as a demonstration.
Unix, Linux and Mac
Ace was conceived and implemented by [[Cyrus Omar|http://www.cs.cmu.edu/~comar]]. Some extensions and work on correctness checking were contributed by Nathan Fulton.