In the United States, political districts define geographic areas which elect representatives including Congress members, state, and local politicians. The boundaries of these districts are redrawn, at minimum, after each U.S. Census to reflect changing populations.

Defining political districts is subject to the issue of "gerrymandering", where influential politicians customize districts to best capture voters sympathetic to their platforms. In an effort to expand public participation in redistricting the Public Mapping Project was launched. This open source project, licensed under the Apache 2.0 license, is a web-based hosted application that lets the public create and contribute their own suggested districts, taking into account the population demographics of a local area.

Anyone can host the Public Mapping Project software on their own servers, and curious users or potential developers can try the demo version now online.

As promised earlier this year, Google has published the source code to their Android OS version 4.0, aka "Ice Cream Sandwich". The popular open source Android OS powers a wide range of smartphones and, increasingly, tablet devices.

There was some concern about whether Google would fulfill their open source commitment by publishing the ICS source code, because the source code to the tablet-oriented Android 3.0 "Honeycomb" was never released. According to Google, their reluctance to released Honeycomb was due to its "rushed" development and issues related to code quality.

Regardless, Android 4.0 ICS is intended to replace prior versions of Android and unify the OS for both smartphones and tablets. Official vendors like Samsung and HTC will decide which devices will either upgrade to or launch with ICS. But because the ICS source is now published, intrepid developers can build their own versions of ICS to produce "custom ROMs" that may run on devices that never receive official support.

Open source design philosophy need not be limited to software. The Open Prosthetics Project is a great example of applying open source principles and licensing to real world products.

In today's world, even basic medical prosthetics can be very expensive. Insurance companies don't always play nice, not to mention people without good or any medical insurance coverage. By developing and publishing prosthetic designs as open source, the project hopes to drive down prosthetic pricing by removing the expense of proprietary intellectual property.

Anyone from hobbyists to manufacturers can view, modify, or build these designs, potentially bringing them to market more affordably than conventional prosthetics. Check out the body-powered hook and the articulated Lego hand! See more projects at the Open Prosthetics Project wiki.

Apple introduced ALAC--the Apple Lossless Audio Codec--in 2004 so that iTunes users could save music from CD's without a sacrifice in quality. Unlike compressed audio formats such as MP3 and AAC, ALAC does not discard any audio information. Its files are larger than MP3 but half the size of uncompressed lossless audio.

Now the code behind ALAC has been released by Apple under the open source Apache 2.0 license. Developers can freely use and modify the ALAC code to add support for Apple's format in their own software and devices.

ALAC is not the only open source lossless audio codec out there, though. FLAC--the Free Lossless Audio Codec--was released in 2001. But Apple iTunes does not natively support FLAC files.