Can bus monitoring tool based on arduino and can bus shield. Implements CAN ASCII/SLCAN protocol compatible with Lawicel CAN232/CANUSB. Can be used for monitoring low speed CAN (interior can bus of most cars, less than 500kbps). For higher speeds serial port can become a bottleneck in case data density is high.
Why do you think that https://github.com/coryjfowler/MCP_CAN_lib is a good alternative to arduino-canbus-monitor