Couchsurfing is a global community of 7 million people in more than 100,000 cities who share their life, their world, their journey. Couchsurfing connects travelers with a global network of people willing to share in profound and meaningful ways, making travel a truly social experience.

The P2P WikiSprint brings together activists, researchers, hackers, journalists, etc. to map and document P2P collaborative experiences

A small NASA experimental project that uses public volunteers (nicknamed "clickworkers" on the site) for scientific tasks that require human perception and common sense, but not a lot of scientific training. Clickworkers are able to work when, and for however long they choose, doing routine analysis that would normally require months of work by scientists or graduate students.

As of today, eMule is one of the biggest and most reliable peer-to-peer file sharing clients around the world. Thanks to it's open source policy many developers are able to contribute to the project, making the network more efficient with each release. At dawn of May 13th 2002 a guy called Merkur was dissatisfied with the original eDonkey2000 client and was convinced he could do better. So he did. He gathered other developers around him, and eMule Project was born.

Global Voices is an international community of bloggers who report on blogs and citizen media from around the world

Freenet is free software which lets you anonymously share files, browse and publish "freesites" (web sites accessible only through Freenet) and chat on forums, without fear of censorship. Freenet is decentralised to make it less vulnerable to attack, and if used in "darknet" mode, where users only connect to their friends, is very difficult to detect.

Wikipedia is a collaboratively edited, multilingual, free Internet encyclopedia that is supported by the non-profit Wikimedia Foundation. Volunteers worldwide collaboratively write Wikipedia's 30 million articles in 287 languages, including over 4.4 million in the English Wikipedia. Anyone who can access the site can edit almost any of its articles, which on the Internet comprise the largest and most popular general reference work, ranking sixth globally among all websites on Alexa with an estimated 365 million readers.

The BitComet program is a multi-threaded multi-protocol hybrid download manager and BitTorrent Peer-to-peer (P2P) file-sharing application. It supports simultaneous download tasks. To complete a particular download, it can draw parts of files from many sources across different P2P and client–server protocols.

Ushahidi is a non-profit tech company that specializes in developing free and open source software for information collection, visualization and interactive mapping.

Arduino is a single-board microcontroller, intended to make the application of interactive objects or environments more accessible. The hardware consists of an open-source hardware board designed around an 8-bit Atmel AVR microcontroller, or a 32-bit Atmel ARM. Pre-programmed into the on-board microcontroller chip is a boot loader that allows uploading programs into the microcontroller memory without needing a chip (device) programmer.