From Drupal and Moodle, right through to a Git versioning system and Perl modules on CPAN, we contribute back to over 175 community open source projects. This list is in order of the number of projects contributed to.
OLPC School Server (http://wiki.laptop.org/go/School_server)
The School Server is one of the products of the OLPC project, designed to complement the XO. It is a Linux-based OS (a Fedora-based distribution) designed to be installed on generic low-end servers.
Objavi is a publishing system for FLOSS Manuals manuals. It converts the books from their native HTML into PDF for printing, or ODF for further processing. This project is related to https://www.ohloh.net/p/booki
Octopus Video (http://octopusvideo.org/)
The social video platform Octopus is the web’s premier 100% open source video hosting and delivering platform. Based on the Drupal platform, Octopus offers services to video contents, providing support for video uploads, enabling you to convert to web-compatible formats for playback in Flash or HTML5, and it’s even compatible for playback on mobile devices like the iPhone, iPad, Android and other mobile setups, or share through social media sites like Twitter and Facebook. Octopus is a product of HEIDI Software and Symphony Themes to focus on video blogging, video community sites like YouTube and business and personal video podcast websites. Octopus is powered by an active community and together we are developing the most advanced management tools for video hosting and delivering.
Odoo is a suite of open source business apps that help you grow your business. Over two million people use Odoo to grow their sales, run their operations, organize marketing activities, boost productivity and empower their human resources. Odoo, formerly OpenERP has been founded in 2005. Odoo thrives in a unique and fully open ecosystem combining the resources of its open source community, partners’ network and vendor. Odoo provides 30 main applications supported by the editor. In addition, the community, comprised of more than 1,500 active members, has contributed more than 4000 apps to cover a wide variety of business needs. -> Formerly known as "Tiny ERP", "OpenERP".
Integration of Google Gears with Moodle for offline caching implementation
Open Source Database Benchmark (http://sourceforge.net/projects/osdb)
The OSDB project is defining a database-independent, system-independent benchmark to enable individuals to analyze the performance of a variety of database and system configurations.
Madison is an open-source, collaborative document editing platform. While Madison can be used to collaborate on many different kinds of documents, the official version is being built with legislative and policy documents in mind.
OpenNMS is the world's first enterprise grade network management platform developed under the open source model. It consists of a community supported open-source project as well as a commercial services, training and support organization.
OpenPhoenux/GTA04 kernel (https://openphoenux.org)
OpenStack Aodh (http://openstack.org)
OpenStack Telemetry (Ceilometer) Alarming