The Linux-Ecology-HOWTO discusses ways to make computers less harmful to our environment and to solve some ecological issues. It explains how to use Linux to save power and consumables like paper and ink. Since it does not require big hardware, Linux may be used with old computers to make their life cycle longer. Games may be used in environmental education and software is available to simulate ecological processes.
GetHT downloads PDF files from Hinduism Today, an "award winning, Macintosh-generated, full color quarterly news magazine articulating Indian spirituality for 135,000 readers around the world." It is the only native GNU/Linux client available, has good proxy support, and allows you to only download the parts of the magazine that interest you.
Arachne is program that implements Avidan and Shamir's seam carving technique for content-aware image resizing. It allows realtime, fluid image resizing using this fascinating technique. Seam carving works by removing the "boring bits" from an image, so it can change the aspect ratio of many images without changing the shape of the objects inside.
Guido van Robot, or GvR for short, is a minimalistic programming language that provides just enough syntax to help students learn the concepts of sequencing, conditional branching, looping, and procedural abstraction. Its biggest strength is that it permits this learning in an environment that combines the thrill of problem-solving with instant visual feedback.
DocBook is an XML vocabulary which enables you to create document content in a presentation-neutral form that captures the logical structure of the content. Using the DocBook Project XSL stylesheets, you can publish DocBook content as HTML pages and PDF files and other formats, including man pages, HTML Help, and JavaHelp.
TextSearch is a program to search through a set of text files in a directory structure. Each document is searched using a regular expression and an overview of the results is shown as a tree structure. By clicking on a file, it can be viewed, with matches being highlighted. As opposed to other programs out there, its focus is not so much on statistics, i.e. how often a word would occur in an entire corpus of files, but rather on occurrences in single files.