At last count, I have heard of TEN!
BreezeBrowser
Canon DPP
Bibble
RAW Shooter Pro
Lightroom/ACR
Capture One
DxO optics pro
Capture NX of Nikon
Silky Pix
Apple's Aperture
And trying out (not really) which is sharpest, rather just watching who is going to win
AjantaKVS