Kig

Open source geometry software

Kig is free and open source interactive geometry software, which is part of the KDE edutainment project. It has some facilities for scripting in Python, as well as the creating macros from existing constructions.

GeoGebra

Open source mathematics application

GeoGebra is an interactive geometry, algebra, and calculus application, intended for teachers and students. Most parts of GeoGebra are free software. GeoGebra is written in Java and thus available for multiple platforms. Many parts of GeoGebra have been ported to HTML5 by using the Google Web Toolkit.

DokuWiki - Open Source Wiki

DokuWiki is a standard compliant, simple to use Wiki, mainly aimed at creating documentation of any kind. It is targeted at developer teams, workgroups and small companies. It has a simple but powerful syntax which makes sure the data files remain readable outside the Wiki and eases the creation of structured texts. All data is stored in plain text files – no database is required. DokuWiki has many features but all of them are easy to learn. And many more can be added through the free plugin downloads

PmWiki - Open Source Wiki

PmWiki is a wiki-based system for collaborative creation and maintenance of websites. PmWiki pages look and act like normal web pages, except they have an "Edit" link that makes it easy to modify existing pages and add new pages into the website, using basic editing rules. You do not need to know or use any HTML or CSS. Page editing can be left open to the public or restricted to small groups of authors.