CAN Boat provides NMEA 2000 and NMEA 0183 utilities. It contains a NMEA 2000 PGN decoder and can read and write N2K messages. It is not meant as an end-user tool but as a discovery mechanism for delving into NMEA 2000 networks.
Why do you think that https://github.com/BMSVieira/nmea.js is a good alternative to canboat