It didn't say is for Maxcoin
It does, keccak (SHA-3) is the algorithm MaxCoin uses. It's an nvidia GPU miner.
Two other coins also use SHA-3. You just can't use any SHA-3 miners. Else why not use use the GPU miner.exe from those SHA-3 coins.
NOTE: the specific Keccak implementation differs a great deal from eCoin... Those trying the eCoin GPUminers will be in for a surprise...
This is exactly why I posted the link.
It is a freshly compiled custom build for MaxCoin's implementation of SHA-3, built by the creator of cudaMiner: cbuchner1.