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 Many of them are outdated.
- BeOS 5, Zeta 1.1 (x86 only)
- Palm OS 5
- RISC OS
- Symbian S60v3 ,and S60v5
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 Many of them are outdated.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 
There are efforts for an unified portable device version.