It’s named AltSoftSerial because it is a software-based serial library that is an alternative to the NewSoftSerial package.

With a price point just below the Arduino Mega 2560 this looks like a great resource for anyone looking to upgrade their Arduino webserver, or just embarrass their Arduino Arduino shield.

It's of course backwards compatible with existing Arduino add-ons, but sets itself apart with a new USB controller with lower latency and driver-free operation on Mac and Linux.