Rawstudio can read and convert RAW-images from
many different cameras, including Nikon and Canon.
Rawstudio uses dcraw.
darktable is a virtual light table and darkroom for photographers. It manages your digital negatives in a database and lets you view them through a zoomable light table. It also enables you to develop raw images and enhance them.
A fast little Web server for embedding.
A telnet server with chrooting, whitelisting, and other security features.