Hi,
The BlitzPlus source code is now available on github:
https://github.com/blitz-research/blitzplus
It's a bit messy (there's probably lots of stuff that can be trimmed etc), and you'll need MSVC 6.0 to compile it 'as is', but it's all there!
I'd also like to reassure Monkey users that when/if I one day 'retire' Monkey (ie: stop selling it), I will also be releasing the full source code to the currently proprietary bits of Mojo in a similar way. Ditto Blitz3D/BlitzMax...
Peace out!
Mark