Zim is a graphical text editor used to maintain a collection of wiki pages. Each page can contain links to other pages, simple formatting, and images. Pages are stored in a folder structure, like in an outliner, and can have attachments. Creating a new page is as easy as linking to a nonexistent page. All data is stored in plain text files with wiki formatting. Various plugins provide additional functionality, like a task list manager, an equation editor, a tray icon, and support for version control. Zim can be used to keep an archive of notes, take notes during meetings or lectures, organize task lists, draft blog entries and email, or do brainstorming.
QMentat helps you practice mental arithmetic. It uses arbitrary-length fixed point arithmetic, and can handle any size numbers, only limited by the size of your screen (and in the case of division with an integer result, the speed at which the number can be factored). It is also quite configurable, allowing you to tailor the questions to your needs.
LibrePlan is a Web application for project planning, monitoring, and control. It is a collaborative tool to plan, monitor, and control projects and has a rich Web interface that provides a desktop-like user experience. All the team members can take part in the planning, which makes it possible to have real-time planning. It was designed for a scenario where multiple projects and resources interact to carry out the work inside a company. It makes it possible to communicate with other company tools, providing a wide set of Web services to import and export data.
spectrwm is a minimalistic tiling window manager that tries to stay out of the way so that valuable screen real estate can be used for much more important stuff. It has sane defaults and does not require one to learn a language to do any configuration. It was written by hackers for hackers and it strives to be small, compact, and fast.
Scid vs. PC is a powerful chess toolkit. It has extensive database and PGN file handling capabilities, and can be used to play chess on the internet (with FICS), against a computer chess opponent, or for chess grandmasters to prepare for tournament matches. Additionally, Scid vs. PC can run automated computer tournaments with chess engines playing against each other.
RSyntaxTextArea is a syntax highlighting, code folding text editor. It has support for over 30 programming languages and is completely customizable. By extending JTextComponent, it easily integrates into any Swing application and provides an easy way to add syntax highlighting to a program.