Requirements - UberWaffe/OpenRA GitHub Wiki

Minimum System Requirements

Running the Game

Hardware:

Shader Model 2.0 capable GPU (Radeon 9500+ / GeForce FX5200+ / GMA X3100+)
1GB Free Hard Drive Space
512MB RAM (the game itself uses ~100MB)
Sound
3 Button Mouse
Network Card (desirable)
Display capable of at least 1024×768

Software Dependencies:

These CLI libraries are cross-platform and included in the thirdparty folder:

SDL2 C#
Eluant
KopiLua (will be dropped in the future)
SharpFont
Mono.Nat
FuzzyLogicLibary

Windows Vista, 7, 8 (x86 and x64)

NET Framework >= 4.0
OpenAL >= 1.1
SDL >= 2.0.2
freetype6.dll
zlib1.dll

Mac OS X 10.6

Mono Framework >= 2.10
XQuartz

Ubuntu 14.04

mono-gmcs
cli-common-dev
libgl1-mesa-glx
libopenal1
libfreetype6
libsdl2

openSUSE 13.1

mono-devel
openal-soft
freetype2
SDL2

Development

Technically anything with git and a text editor, but you probably want at least the requirements to run the game, plus:

Software:

Git
A C# compiler (Mono’s CGC, xbuild/msbuild)
An IDE like MonoDevelop/Xamarin Studio, Visual Studio (Express)

Mac OS X

Install fink, then install glib2-shlibs and glib2-dev. (possibly not the first, try just glib2-dev and pkgconfig)