This page describes different Android projects related and supported by tinkerphones

Replicant

Replicant is a fully free Android distribution running on several devices. It is a free software project. This Android distribution is the most advanced for the GTA04, please refer to our gta04-replicant project: http://projects.goldelico.com/p/gta04-replicant

Also, the upstream Replicant project is working on official support for the GTA04:

http://www.replicant.us

Cyanogenmod

CyanogenMod is an aftermarket firmware for a number of cell phones based on the open-source Android operating system. It offers features not found in the official Android based firmwares of vendors of these cell phones.

http://www.cyanogenmod.com/

AoF

Port of the Andoid OS to the Openmoko Freerunner (does not work on GTA04)

http://code.google.com/p/android-on-freerunner/