Why doesn't any Linux/Mac games developer make an Spiritual Succesor to Elemental for those platforms?* Valve? Blizzard? Any of the "locals"?
Even if Stardock were to diversify in the near future (where "near" could be "no less than some years" as far as my total ignorance about the topic goes), right now there seems to be no real reasons for them to go beyond their Windows scope, despite Linux/Mac fans not agreeing with their reasons (as in many many many many times and threads mentioned already). Even less to release the source code (as in also mentioned like a lot of times too...).
* Oh my, I feel dirty and evil now.
*hides under a rock*