Ghostscript is a processor for PostScript and PDF files. It can rasterize these files to a wide variety of printers, devices for screen preview, and image file formats. Since applications tend to prepare pages for printing in a high-level format such as PostScript, most Unix users with low-level bitmap printers, such as inkjets, use GhostScript as part of the printing process. In addition, Ghostscript is capable of converting PostScript files, functionality comparable to Adobe Acrobat Distiller, but on the command line. In addition, Ghostscript is used for file import and viewing by a great many other applications, including xv, ImageMagick, gimp, and xdvi. Several GUI wrappers for viewing PostScript and PDF files exist, including GSview, ghostview, gv, ggv, and kghostview. This is far from a comprehensive list.
album is a free HTML/XHTML photo album and gallery generator that supports themes/skins. You can choose different themes or write your own to get different layouts and styles. It creates all your thumbnails (including directory thumbnails) and descends into directories so you can organize your photos. See the home page for more examples. album is also multi-lingual, with many languages being added all the time. N.B.: The purchase link is provided for donations; the software does not cost anything.
Jmol is a Free, Open Source molecule viewer and editor. It is a collaboratively developed visualization and measurement tool for chemical scientists. Jmol is an active project, and there are new features being added to it on a daily basis. Users are encouraged to modify it to fit their needs and to contribute their changes to the project.
Mup produces very high quality PostScript printed music or a MIDI file from a text input file. It can handle almost any kind of music, instrumental or vocal, including tablature, shaped notes, guitar grids, alternate tunings, user-defined symbols, and much more. Mup has been under active development since 1992.
Sfront compiles MPEG 4 Structured Audio (MP4-SA) programs into efficient C programs that generate audio when executed. MP4-SA is a standard for normative algorithmic sound, which combines an audio signal processing language (SAOL) with score languages (MIDI and SASL). Under Mac OS X and Linux, sfront supports real-time, low-latency audio input/output and MIDI input. Under Mac OS X, sfront supports the creation of AudioUnit plug-ins. The documentation includes a book about SAOL programming.
Argyll is an ICC compatible color management system. It supports accurate ICC profile creation for scanners, CMYK printers, and film recorders, and calibration and profiling of displays. Spectral sample data is supported, allowing a selection of illuminants observer types, and paper fluorescent whitener additive compensation. Profiles can also incorporate source specific gamut mappings for perceptual and saturation intents. Gamut mapping and profile linking uses the CIECAM02 appearance model, a unique gamut mapping algorithm, and a wide selection of rendering intents. It also includes code for a fast 8-bit raster color conversion engine as well as support for fast, fully accurate 16-bit conversion. Device color gamuts can also be viewed and compared using a VRML viewer.
The Interverse is the evolution and combination of the Web, chat, instant messaging (IM), and voice communication. It is not just a graphical user interface (GUI), but an immersive user interface (IUI). The Interverse is a virtual universe running on top of the Internet. It uses the Crystal Space 3D engine to render the user's view of the world.