Two things. Feel free to start your own open source project with my Java source code. I suggest SourceForge or Google. And my only suggestion is not to use "Magic: The Gathering" in the description, but instead just use "trading card game". Zip file with the full program and source code, download it here.
Secondly, when the computer blocks with multiple blockers a window should popup but doesn't. I should fix this soon. I think a previous version won't have this problem, download it here. Thanks for the error reports.