Image Alchemy has the ability to convert between over 90 different raster image formats (including all colorspace and compression variations of each format). Color management features include gamma correction, undercolour removal, seven high quality dithers, colorspace conversion, and palette manipulation. It also includes a Postscript interpreter.
Piwigo is photo gallery system for the Web. The project started in 2002 and is built by an active community of users and developers. It comes with powerful features for publishing and managing your photos, scalability, and smart browsing capabilities such as albums, tags, or calendars. Extensions make Piwigo even more customizable.