JFX, you have to realize that the reason a game like FreeCiv can be made available for the Internet Tablets is because its source code is available in order to compile executables that work on ARM processors. That's not the case with Age of Empires or Diablo 2 - those are closed source games that have only been made available in already-compiled form for x86 processors by their publishers and cannot be ported to the ITs.

In some cases, the open source community will write an open reimplementation of a game's engine to bring it to new platforms - Jagged Alliance 2 is an example - but that's not a quick "port", but usually represents a multi-year reverse engineering and implementation effort by a dedicated team of enthusiasts.