Ruid2 is based on mod_ruid and mod_suid2 but it has better performance than mod_suid2 because it doesn't need to kill httpd children after one request.

it makes use of kernel capabilities and after receiving a new request suids again. there are some security issues, for instance if attacker successfully exploits the httpd process, he can set effective capabilities and setuid to root. for this reason, it is recommended to be used in conjunction with a kernel security patch (eg. grsec).