Mappy 0.9d is the 4th release of the Mappy Virtual Machine and the first release to be Open Source. The complete source code to both the Mappy VM user interface and the Mappy VM core is available under the Bottled Light Public License, similar in terms to the MPL.
The binary version of Mappy VM 0.9d is an interim release to accompany the source code. In addition to a number of bug fixes, 0.9 is also considerably faster than 0.8. Most of the viewers have also been improved and the source debugger has been rewritten from scratch.
More information, binaries, and source code can be found at http://www.bottledlight.com/mappy