Download Rawzor
(For Windows, Free Beta v0.47)
Or download rawzor for mac osx
Get RWZ SDK (for developers).

Rawzor uses lossless image compression to compress camera raw images with zero loss in image quality or meta-information. Compress your photos with absolutely no change in the original raw file.

Save upto 20% to 60% space, totally lossless. Get back the exact raw file, every byte of it.
Supports almost all raw formats and cameras (view list).
Makes it easier to manage storage, backup, archival, upload, download, dvd transfer etc.
Screenshot
Rawzor Screenshot (on Windows)
Rawzor vs Zip vs Rar
Compression ratio depends on a number of factors like the camera model, image content, noise level, quality of in-camera compression etc... these results were prepared from a 0.4 Terabyte collection of raw images. See list of supported formats and cameras.
(Click on images to enlarge instantly)