Pulsar was originally released for windows in 2009. I"ve compiled it now for Mac and Linux. Few edits to make it compile but same code as original pulsar2009-9b. Linux code is identical to Mac. Download at http://www.lanternchess.com/pulsar/
Can play Chess, Crazyhouse, Atomic, Giveaway, Suicide, Loser's, Three Checks, Fischer Random, Shatranj, 2King, as well as various seaboard wilds. It supports analysis mode in Atomic, Loser's, Giveaway/Suicide, Crazyhouse, 3Checks and regular chess.
I've been running it in Xboard on a computer account for a few days on mac, no issues. As some know i have made a Java interface to chessclub.com at http://www.lanternchess.com and Pulsar can be loaded into that for analysis in ICC examine mode in different variants with Options / Load Winboard Engine.
The binaries are freeware per the license on the page.
Mike