This is a fork of the BLHeli_S open source sensorless brushless motor electronic speed control (ESC) firmware. It was created in an attempt to revive open source development of this type of firmware, and make modern features available to users of open source software.
For flashing and configuration, get the latest version of BLHeli Configurator from here. The latest releases of BLHeli_S are downloadable from within the Configurator, or the hex files can be downloaded from here.
For more information, check out these threads:
https://www.rcgroups.com/forums/showthread.php?2640796 (for BLHeli_S)
http://www.rcgroups.com/forums/showthread.php?t=2136895 (for BLHeli)