It is licensed under the 2-clause BSD-like license and it runs on Linux, BSD variants, Mac OS X, Solaris, AIX, HP-UX, as well as on other *nix flavors. It also has a proof of concept port for ...
Be very careful that enabling the cache may cause inconsistencies. For example, if you enable caching of boottime on Linux, be aware that unintended values may be returned if the boottime is changed ...