jhPrimeMiner is a miner that was designed for use with the http://www.ypool.net pool, the very first primecoin pool for miners.
Official thread: http://ypool.net/howto.php
Unofficial thread: https://bitcointalk.org/index.php?topic=257623.0
Current releases for Windows, Mac, and Linux-wine can be found here: http://azbowling.com/AeroCloud/
There are several variants of this miner in development from several different developers.
"It is quite similar to the Mumus build but does not do the large divisor test anymore since others have said this part is buggy and wastes a bit of time. It also has the -h parameter which specifies what length of chain to search for (default 9 which is the case for all current miners) and it removes some unused fermat test branches and other calculations."
rdebourbon's dropbox: https://www.dropbox.com/sh/sq24hzo993afy9c/l7icP0KiuM
Source code can be found at his github: https://github.com/rdebourbon/jhPrimeminer