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.
Bacula is a set of programs that allow you to manage the backup, recovery, and verification of computer data across a network of different computers. It is based on a client/server architecture and is efficient and relatively easy to use, while offering many advanced storage management features that make it easy to find and recover lost or damaged files.
Benchw provides a toolset to benchmark the capabilities of several different database engines for data warehouse type activities. It is designed to provide a simple way to test data loading, index creation plus query performance in the spirit of TPC-H
An object-oriented library written in PHP that allows reading and writing iCalendar files. It is easy to use, fully standards compliant, and powerful. Intended audience: application developers who want to support iCalendar (RFC-2445, iCal).
Bizgres is a PostgreSQL "distribution", including experimental core mods, for an optimized Business Intelligence version
Booktype (formerly known as Booki) is the open source platform that helps people write and publish print and digital books. Booktype makes it easier for people and organisations to collate, organise, edit and publish books. Delivering frictionlessly to print, lulu.com and almost any ereader, Booktype facilitates collaborative production processes. No more lost manuscripts, overwritten Word files, awkward wikis or cumbersome CMSes. This project is related to https://www.ohloh.net/p/objavi
CPAN-API (metacpan backend) (http://www.metacpan.org/)
A free, open API for everything you want to know about CPAN. Also serves as the backend for the metacpan.org web site.
WARNING: Chiba development has stopped in 2010. The betterFORM Project (http://www.betterform.de) is the successor of Chiba. See https://www.ohloh.net/p/betterform.
Crypt::OpenPGP is a pure-Perl implementation of the OpenPGP standard. In addition to support for the standard itself, Crypt::OpenPGP claims compatibility with many other PGP implementations, both those that support the standard and those that preceded it.
DAViCal CalDAV & CardDAV Server (http://www.davical.org/)
The DAViCal CalDAV & CardDAV Server is a server implementation of the CalDAV and CardDAV protocols for storing calendaring (iCalendar format) and addressbook (VCard) resources on a remote shared server. An increasing number of calendar clients support the maintenance of shared remote calendars through CalDAV including Mozilla Calendar (Sunbird/Lightning), Evolution, Mulberry, Chandler, KDE pim (Koraganizer ) and soon Apple's iCal. DAViCal supports basic delegation of read/write access among calendar users and multiple users or clients reading and writing the same calendar entries over time.