This page is for the original version. For the remake, see Heroes of Might and Magic III HD.
The Mac OS and Linux versions of the game are no longer sold, and existing copies of those are hard to run on modern systems. The easiest solution for running the game on Linux or OS X is buying the Windows version and running it under Wine. Further information on how to do that can be found on AppDB. Alternatively, VCMI can be used to run the game.
An unofficial expansion pack adding further units, resources and easier modding possibilities. The official English website is located under Celestial Heavens. Currently isn't in development any more.
Another unofficial expansion pack adding more features, units, resources and another town. The official thread on Heroes Community.
Not actually a mod, but an attempt at rewriting the whole engine to make it customizable, portable and fully cross-platform. The official website of the project is here.