aSysBus is hard- and software to build a network of arduino nodes using a CAN-bus or other interfaces. It was build as a replacement for iSysBus(DE), which used native AVR code and a java based configuration framework instead of Arduino. It is mostly used for home automation and other control communication.
For CAN communication the library Seeed-Studio/CAN_BUS_Shield is required. We created a fork with some special additions to support sleep mode. A pull request for these additions is pending, check if it was already merged.
Take a look around the wiki to learn more about the protocol, the included examples should help to get you started. If you speak german there are several videos over at YouTube.