Its an open source Java library that includes the CruiseControl plug-in, an API to make your wildest X10 dreams come true, detailed instructions, and an ever-so-useful collection of tests. Way down deep, the library uses the Java Communications API to send bits out over the serial port and into the Firecracker Computer Interface. (Linux users will need the RXTX implementation). Michel Dalals Java X10 CM17A API library, an implementation of the FireCracker (CM17A) Communications Specification, is used to send out the correct 1s and 0s in response to human-friendly commands. Many thanks to him for doing all the low-level bit twiddling and sharing the goodies with us!