1. go to http://os.inf.tu-dresden.de/download/snapshots-oc/, get the latest snapshot and extract
2. run make setup in main folder, choose ia32 (others seem to be not working), there will be some errors but it is easily fixed
3. run make -jX in main folder, with X is number of cores that u want to use to build it
4. run make qemu in obj/l4/x86, choose any application that you like
5. if it fails, create your own fiasco and/or l4 in src/kernel/fiasco/ and/or src/l4/ and use l4linux build in obj/l4linux/ux

i made this, since this instruction http://l4linux.org/build.shtml seem to be failed