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.
QCad is a powerful but easy to use 2D CAD program for Linux, Windows, and Mac OS X. It uses DXF as its standard file format. While other CAD packages are often rather complicated to use, QCad tries to stay comfortable, and even an absolute beginner can create professional drawings with a minimum of effort.
XaoS is a fast, portable, real-time, and interactive fractal zoomer. It displays the Mandelbrot set (among other escape time fractals) and allows you zoom smoothly into the fractal. Various coloring modes are provided for both the points inside and outside the selected set. In addition, switching between Julia and Mandelbrot fractal types and on-the-fly plane switching is provided.
There are many photo-gallery programs available. Zoph is different, as it concentrates on the management of large collection of photos instead of just showing them on the Web. It can store a lot of information about your photos, including the regular EXIF info, photographer, location, title, description, rating, and the people in the photo. Photos can appear in multiple albums and categories. Additional features include search, slideshows, lightboxes, email, access privileges, and multiple languages.
Tux Paint is a simple and entertaining drawing program geared towards young children. It has a simple interface, sound effects, and a cartoon character (Tux, the Linux penguin). Along with drawing brush strokes, lines and shapes, you can also enter text and place "rubber stamp" (or "sticker") images on the picture. Tux Paint is extensible, and could be useful in an educational environment (such as a grammar, elementary, or grade school). It's portable across numerous platforms, and runs well even on slower systems like the Pentium 133MHz.
Asymptopia Crossword Builder (Math/Text) is an application that runs in any modern Web browser, but does not require an Internet connection (if it is installed locally). The application was designed to allow teachers to quickly produce well-designed, challenging activities. The application features a configuration panel where the user can either enter their own word-hint pairs, or generate math-crossword problems via a single button. The math functionality generates word:hint pairs like: "four:7/x-3/8=11/8", where the hint corresponds to the problem, and the student would write the letters "four" in the corresponding boxes of the puzzle.
GeoServer is a software server that allows users to share and edit geospatial data. Designed for interoperability, it publishes data from any major spatial data source using open standards. GeoServer is the reference implementation of the Open Geospatial Consortium (OGC) Web Feature Service (WFS) and Web Coverage Service (WCS) standards, as well as a high performance certified compliant Web Map Service (WMS). GeoServer forms a core component of the Geospatial Web.
Ansel is a Horde photo gallery that provides functionality for managing unlimited photo galleries, with thumbnails, paging, EXIF data, and permissions on a per-gallery basis. It also provides a number of features not normally found in Web-based photo galleries, including cropping, resizing, rotating, watermarking, and greyscale effects.
Alexandria is a GNOME application to help manage a book collection. It retrieves book information (including cover pictures) from several online libraries, allows you to search for a book (either by EAN/ISBN, title, authors, or keyword), can import and export data into ONIX, Tellico, and EAN/ISBN-list formats, generates Web pages from your libraries, allows marking your books as loaned, saves data using the YAML format, features an HIG-compliant user interface, shows books in different views that can be filtered or sorted, and handles book rating and notes.