Quoting the license code:
MiniGL may only be compiled for/ incorporated in code running on AmigaOS.
I understand that as restriction for coders, that they may only compile their programs/games for AmigaOS.
However, in my opinion it doesn't say, that end users may not use the compiled binary on other systems able to run AmigaOS executables (MorphOS, UAE, Amithlon etc...)
EDIT:
And I sure can't see any mention of such restrictions on my Heretic II box...