Loadman is still maintaining Mala, though I believe he's gotten sidetracke by life over the last year or so.
Mala was originally written by Swindus and when Loadman took over, I believe the agreement was to keep it closed source.
That was primarily because Mala uses some video libraries (and possibly other libs) that are commercial, and so open sourcing Mala proper wouldn't much help if you didn't have those libs.
Finally, I believe Malas written in turbopascal or some such, ie not a particularly common language anymore.
Personally, it might still be nice to open source it, if only to make porting to .net or some other language a bit easier. But that's a call loadman would have to make (possibly after talking with the original author).