Replicant is a free and open source operating system, written in C. It is based on the Android mobile platform and aims to replace all proprietary Android components with free software counterparts. It is available for several smartphones and tablet computers.
The name Replicant is drawn from the fictional replicant androids in the Blade Runner movie. Replicant is sponsored and supported by the Free Software Foundation.
The Replicant project started in mid-2010 with an effort to consolidate various initiatives attempting to produce a fully free-as-in-freedom Android derivative for the HTC Dream. The original team consisted of Bradley M. Kuhn, Aaron Williamson, Graziano Sorbaioli and Denis ‘GNUtoo’ Carikli. The project quickly led to the writing of replacement code for the non-free parts that were required to make the HTC Dream functional. The first component to be replaced permitted audio to work without a proprietary library. Replicant originally provided its own FOSS application repository, which was later replaced by F-Droid.
The Radio Interface Layer, software that handles communication with the modem, was replaced by free code, thus making the telephony part usable. A library handling the GPS was then adapted from free code that was originally written for another phone and permitted the HTC Dream to have GPS working with Replicant.
Early versions of Replicant were based on the Android Open Source Project code, while versions 2.2 (April 2011) and later used CyanogenMod as their base, in order to make supporting more devices easier. In a blog post on on February 1, 2017, the Replicant project said the future versions of Replicant will be based on LineageOS, as the CyanogenMod project was discontinued.
As development continued, many members of the original Replicant team retired from the project, making Denis "GNUtoo" Carikli the only remaining member from the original team still actively working on the project. In April 2011, Paul Kocialkowski decided to get involved with the project and gradually became the main Replicant developer, after successfully porting it to the Nexus S and Galaxy S devices.
Replicant is sponsored and supported by the Free Software Foundation, which also hosts Replicant's source code.
The following table lists major releases of Replicant:
In March 2014, Replicant developers found and closed a vulnerability present in a wide range of Samsung Galaxy products that allowed the baseband processor to read and write the device's storage, sometimes with normal user privileges and sometimes as the root user depending on device model. Replicant's lead developer Paul Kocialkowski claimed it was a backdoor, but this was contested by Dan Rosenberg, a senior security researcher at Azimuth Security, who said there was "virtually no evidence for the ability to remotely execute this functionality".
On January 3, 2013, the project released Replicant 4.0 SDK as a fully libre replacement to Android SDK. The Replicant SDK was released in response to Google updating the license for add-ons and binaries under a proprietary agreement.
Scope of the Replicant project has been gradually expanded to include support for new devices, starting with the Nexus One, Nexus S and Galaxy S. As of January 2014, the following devices are supported, with Wi-Fi and Bluetooth requiring proprietary firmware in order to work:
Additional target devices are evaluated, based on the suitability of their hardware platforms and required device drivers; as of January 2014, devices listed below are not yet supported, and porting Replicant to them is only in consideration.
In November 2013, it was announced that Replicant could work on a Fairphone device and that the bootloaders may even be free software. The Fairphone team seemed "definitely interested" in helping to get Replicant ported to the device. In December 2014, Fairphone admitted that it had failed to convince chipset vendor MediaTek to open up the source code for first-generation Fairphones.
Based on either the unsuitability of their hardware platforms or the lack of available free software drivers, porting Replicant to the devices listed below has been considered and rejected.