Windows
Minimum:
OS: Windows 7/8/8.1/10
Processor: PC with 1.0GHz Intel® Pentium® III equivalent or higher processor
Memory: 256 MB RAM
Graphics: DirectX 9/OpenGL 4.1 capable GPU
Storage: 250 MB available space
Sound Card: DirectSound-compatible sound card
Additional Notes: 1024x768 or better video resolution
Linux
Minimum:
OS: Ubuntu 14.04 or Steam OS 2.0 (64 bit)
Memory: 256 MB RAM
Storage: 250 MB available space
Additional Notes: Editor best in Desktop mode (Steam OS)
Mac
Minimum:
OS: Mac OSX 10.10 or better
Processor: Intel Core2 Duo or better
Memory: 256 MB RAM
Graphics: Compatible OpenGLR
Storage: 250 MB available space
Sound Card: DirectSound-compatible sound card
Additional Notes: 1280x768 or better Display