ExtenDOS 4 has been tested under a wide variety of operating systems used on Atari TOS-based machines. The following operating environments are currently supported:
 | TOS (all versions) |
| MultiTOS (with MiNT v1.08 or v1.12) |
| Geneva (all versions) |
| MagiC (v2 through v6 tested) |
For the latest support information, please contact Anodyne Software.