The operating system (OS) is the main software system on your computer running all the programs that you want to run.
OpenTTD currently runs on operating systems listed below:
- Linux (NOTE: different Linux variations and distributions behave differently, but some of them include OpenTTD in their packaging system in up-to-date version)
- MacOS X (Due to the lack of a MacOS X developer, the port was not officially supported for the 1.0.x branch. However, support has been resumed for the 1.1.x branch)
- ReactOS with the Windows binary
- Windows 95/98/ME/2000/NT/XP/Vista/7
Ports on operating systems listed below are not supported. This means that these binaries are not maintained by the OpenTTD developers. Many of them are outdated.
Additionally OpenTTD runs on different devices listed below. Note that none of these ports are supported by the OpenTTD developers. Many of them are outdated.
- Apple iPhone / iPod Touch 
- GP2X 
- Nokia N-series (Maemo)  and  (from )
- Nintendo DS 
- Nintendo Wii
- Pocket PC 
- PSP 
- UIQ3 
- Zaurus PDA 
There are efforts for an unified portable device version.