Joomla is a largely used open source content management system based on MySQL / PHP. Several personal websites, corporate websites, blogs, forums, online communities and networks have installed Joomla for stability, easy usage and flexibility.
Tornado is an open source version of the scalable, non-blocking web server and tools that power FriendFeed. The FriendFeed application is written using a web framework that looks a bit like web.py or Google's webapp, but with additional tools and optimizations to take advantage of the underlying non-blocking infrastructure.
Zomobo is a web application structured thematically around topics, like in an encyclopedia, enhanced with a set of features and interactive functions. It integrates contents loaded from different online sources under one single interface ..
The PHP PEAR also known as PHP Extension and Application Repository, is a repository built especially for PHP software code. In this tutorial, you will learn how to install the PHP PEAR on the linux server. Install PEAR allows you to install various extensions without compiling the source packages.
"Otr.to - p2p chat, that mean you communicate directly, no logs saved on server
Otr.to absolutely anonymous, registration free
Otr.to browser based, that mean you don't need to install or ask somebody to install software
Otr.to use OTR (Off-the-Record Messaging) - most secure cryptographic protocol
Otr.to Open-source and written in JavaScript, that mean you can check how it works"
"Mind Map Maker, a free, fully HTML5-compliant with cloud support mind mapping webapp. This is a prototype of an HTML5 based mind mapping application. It lets you create neat looking mind maps in the browser But did you know that it is available offline? You can use the app wherever you are, there is no need for an internet connection, everything happens inside your browser on your machine. This one is free, open source and it's full of HTML5 goodness."
The list below is a container for all kinds of enabling softwares. Many of them are open source. Probably the most interesting ones are the frameworks, platforms and libraries for typical 2.0-stuff .
But watch out for all other pearls: bug & issue trackers, business intelligence solutions, database solutions, catalogue wares, design toolboxes, enterprise solutions, media editors, hosting & domain management & testing tools, media management solutions, mobile content delivery tools, site tour builders, hardcore telephony solutions, voice recognition tools, and more incidental code snippets, like URL shorteners, widget builders, Ajax & RIA apps.
"Bisq is an open-source desktop application that allows you to buy and sell bitcoins in exchange for national currencies, or alternative crypto currencies."