The XV "jumbo" patches are a pair of aggregate patches against XV 3.10a, which was last released in December 1994. The first jumbo patch incorporates roughly two dozen bugfixes. The second patch encompasses almost as many enhancements, including support for additional image formats like PNG, PhotoCD, and PDF; performance improvements; and new features such as mouse-wheel support, alpha blending against a background color, and improved dithering for 15/16-bit displays. All patches available from the official XV site are included, as well as numerous other patches from around the world.
pngquant is a batch conversion utility to quantize and dither truecolor PNG images, especially those with a full alpha channel, down to "RGBA-palette" PNGs (i.e., PLTE + tRNS in PNG parlance). Such images are usually two to four times smaller than the full 32-bit versions, and partial transparency is preserved quite nicely. This makes pngquant especially useful both for Web sites and for PlayStation 2 development, where one of the texture formats is RGBA-palette-based (though not PNG-compressed).
Jitac is a Java application that converts images into ASCII art by associating blocks of the image with ASCII characters. It supports several image formats (GIF, JPEG, TIFF, and PNG) and some image manipulations that can be performed before the conversion (inversion, grayscale, resize, and gamma correction).
RPhoto is a handy image editor to simplify cropping of digital camera pictures and avoid white borders introduced by incorrect height/width ratios. It also has lossless rotate and flip features, as well as a unique way to rectify a bad angle by only drawing a horizontal or vertical line.
Picasa is Google's photo organizer. It makes it easy to find, edit, and share digital photos. It automatically locates and remembers all pictures and sorts them into visual albums organized by date with recognizable folder names. You can drag and drop to arrange albums and make labels to create new groups. This Linux version mostly has the same features as the Windows version, and is based on a modified version of Wine.