This is another unexpected port like Android in Iphone , Quake 3 has been already ported to Motorola Droid successfully  sometime back but now hackers/developers who were testing in this Quake has hacked to the next level. Now Quake 3 is ported to Nexus One which runs under android successfully. After the months of harkwork and dedication and technology implementation ,it is now fully working working and you can enjoy every moment of Quake in Android.

Here is the Video which might make it more clear for you to understand and how it was done in Nexus one phone,

Android 1.6 or above OS version only will support the Quake and   The binaries and installation instructions can be reviewed from  Google Open Source project website.