oFono.org is a place to bring developers together around designing an infrastructure for building mobile telephony (GSM/UMTS) applications. oFono is licensed under GPLv2, and it includes a high-level D-Bus API for use by telephony applications of any license. oFono also includes a low-level plug-in API for integrating with open source as well as third party telephony stacks, cellular modems and storage back-ends

The Echo Nest Remix API lets you manipulate music and video from the web. We've done the following: rearranged the syllables of a vocal line, walkenized and cowbellized hundreds of thousands of songs in a week, mixed up the hits of a drum beat and synced it to another loop, beat matched two songs, split apart DJ mixes by their individual tracks, made new kinds of music, synced a video to a song, transitioned between two covers of the same song, made a cat play piano. We're making this available as an open source SDK for Python that can currently be easily installed for Mac OS X and Linux. It accesses the Echo Nest Analyze API at http://developer.echonest.com seamlessly through a web services interface and parses the results. You'll need an Echo Nest API key to use this SDK.

The GeoNames geographical database is available for download free of charge under a creative commons attribution license. It contains over eight million geographical names and consists of 6.5 million unique features whereof 2.2 million populated places and 1.8 million alternate names. All features are categorized into one out of nine feature classes and further subcategorized into one out of 645 feature codes. The data is accessible free of charge through a number of webservices and a daily database export.

Supervisor is a client/server system that allows its users to monitor and control a number of processes on UNIX-like operating systems.

The Django REST interface makes it easy to offer private and public APIs for existing Django models. New generic views simplify data retrieval and modification in a resource-centric architecture and provide model data in formats such as XML, JSON and YAML with very little custom code.

Gears is an open source project that enables more powerful web applications, by adding new features to web browsers.

The goal is to develop a "computational engine" for Verse, based on plug-ins. You can think of Purple as sort of the back end of an ordinary 3D package. It allows developers to write small pieces of functionality, called plug-ins, that can be connected together to get things done. Since the user interface ("front end") is completely separate, anyone can do their own if they desire.

The Echo Nest is a music technology company founded by two MIT Media Lab PhDs. The Echo Nest’s proprietary music analyzer API automatically analyzes audio (e.g. aif, wav, mp3, m4a), and generates an XML file that describes the musical and structural content of the music. That representation can help power music visualization, music games, artistic installations, content-based and DJ applications with a much deeper level of music understanding. For developers, the Echo Nest technology facilitates more efficient, relevant and robust audio data extraction.