Nice CANopen stack that works and that can be ported easily. Sadly the project is not actively maintained anymore. Mailings to the mailing list are not answered and valuable patches and contributions are ignored. Maybe this is the reason for some forks of this project. If you are looking for an actively maintained CANopen stack you may better consider the CANopen Node project: https:||sourceforge.net|projects|canopennode Development of this project is very active. Patches are welcome and questions will be answered by maintainer. A problem of the CanFestival stack is also, that it does not provide an interface for hardware CAN message filtering. This is a problem for small embedded devices on heavy bus loads. The CANopen Node stack supports setting of hardware message filters. We are currently porting a CANopen stack for eCos realtime OS an considered CanFestival but now we are switching to CANopen Node stack because it is actively maintained.