Replicant is a free and open-source Android-based operating system that intends to replace all proprietary Android components with free-software counterparts.

[11][12] 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 device.

[13][14][15][16] The project quickly led to the writing of replacement code for the non-free parts that were required to make HTC Dream functional.

[18] The Radio Interface Layer software that handles communication with the modem was replaced by free code, thus making the telephony part usable.

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.

[28][29] The following table lists the 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,[37] sometimes with normal user privileges and sometimes as the root user depending on device model.