FAI can install different Linux distributions like Redhat, CentOS, Scientific Linux Cern, Fedora, openSUSE, SuSE, Ubuntu and of course Debian.
Read the announcement including a small HowTo.
Distribution specific stuff
FAI 4.0 includes examples for installing CentOS 5 and 6. Ready-made basefiles are available at http://fai-project.org/download/basefiles/. Sample log files for a CentOS 6 installation can be found here
Scientific Linux Cern
FAI 4.0 can also install SCL 5 and 6. Ready-made basefiles are available at http://fai-project.org/download/basefiles/.
RHEL5 and 6
Redhat Enterprise Linux 5 and 6
This should work in the same way as CentOS and SLC.
A more verbose description on how to do this with SLES9 is available here
Bootstrapping the base images for other distributions
Have a look at examples/simple/basefiles/mk-basefile. Works for Ubuntu, CentOS, SLC. For RPM based distributions it uses rinse, which also support some old versions of OpenSUSE.