The current supported platforms: Linux It needs kernel 2.4 or higher and the libacl library installed (with development headers, if installing from rpm). The url is http://acl.bestbits.at if using for ext2/ext3 and JFS, and http://oss.sgi.com/projects/xfs/ if using for XFS. The level of compliance is level 2 (see IMPLEMENTATION). FreeBSD The current tested version is 4.6. I hope to be able to test 5.0 after it's released. The level of compliance is level 1. I hope that in FreeBSD 5 they will improve. For any other platform, volunteers are welcome. To add support, look into setup.py at first and then into acl.c