The public open beta is now also available for linux!
Important note for the linux release:
Please start the game using the "startprojectw.sh" script. The game uses the BASS audio library, so linux needs to know where to locate the libbass.so. This script ensures this.
Also note that the linux version was compiled with a different compiler than the windows one, so there may be bugs present on linux that aren't present on windows.
Note that game requires OpenGL 2.0, so make sure you've got OpenGL acceleration setup on linux and that your graphics card supports at least OpenGL 2.0.
Behind the scenes
Porting the game over to linux wasn't easy after all and it took me almost a full month of countless hours of coding (after my day job as a software engineer). The windows release was made with Embarcadero's Delphi which is de-facto only available for windows and included more than 120,000 lines of code with lots of windows-only stuff.
So in order to get the game ported over to linux I had to replace all the windows-related stuff (setting screen resolution, loading XML, the sound library, etc.) with code that would run and compile on both platforms. That meant replacing several external dependencies (e.g. microsoft's XML libs) with my own stuff (having me write new code for things that worked for years now), adding a lot of compiler defines so that certain code get's used when compiling for windows vs. different code only used when compiling for linux.
And since Delphi isn't available on linux a also had to move over ot another development environment. I went for Lazarus (with free pascal as the compiler) as it's object pascal too and pretty close to Delphi. But still there were some (partly game-breaking) differences between the two compilers making me change another big part of the code to get them to work with both.
But in the end, after all these countless hours of work, the game's code now runs and compiles fin on windows and linux, so from now on all future release will be released for both operating systems.
And I also want to add Mac OSX support sometime in the future, though that may not happen this year.
So I hope all linux users out there that like turn-based strategy games can now enjoy "Phase 2" of Projekt Weltherrscher too!