WTF
mod_ruid is suexec module for apache 2.0, based on mod_suid2

-it runs only on linux because afaik only linux has implemented posix 1003.1e c
 apabilities
-it has better performance than mod_suid2 because it doesn`t need to kill httpd
 children
 after one request. it makes use of kernel capabilites and after receiving a ne
 w 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. i recommend to use some
 security patch in kernel (grsec), or something..

-there are two main operation modes: stat and config
 1. stat is default, httpd setuid and setgid to uid and gid of requested
 filename(script)/directory this is good if you use mod_vhost_alias for virtual
 hosting

 2. config
 like mod_suid2, you must define uid and gid

INSTALL
 1. download and install latest libcap from here
 2. run /apachedir/bin/apxs -a -i -l cap -c mod_ruid.c
 3. configure httpd.conf
 4. restart apache

CONFIGURE OPTIONS:
 RMode config|stat (default is stat)
 RUidGid user|#uid group|#gid - when RMode is config, set to this uid and gid

 RMinUidGid user|#uid group|#gid - when uid/gid is < than min uid/gid set to
 default uid/gid
 RDefaultUidGid user|#uid group|#gid

 RGroups group1 group2 - aditional groups set via setgroups

 RCoreDump - on or off, if on, you can have coredumps of httpd after crash
 (default off)
 RCoreDumpSize - limit size of coredump in bytes, 0 is unlimited (default 0)

EXAMPLE:

LoadModule ruid_module   modules/mod_ruid.so
User                     apache
Group                    apache
RMode                    stat
RGroups                  apachetmp

# uncoment if you want coredumps after httpd crash (coredump direcory must have
# 777 permissions)
#RCoreDump              on
#CoreDumpDirectory      /usr/apache/core

NameVirtualHost 192.168.0.1
<VirtualHost example.com>
  ServerAdmin    webmaster@example.com
  DocumentRoot   /home/example.com/public_html
  ServerName     example.com
  ServerAlias    www.example.com
  RMode          config
  RUidGid        user1 group1
  RGroups        apachetmp
</VirtualHost>

<VirtualHost example.net>
  ServerAdmin    webmaster@example.net
  DocumentRoot   /home/example.net/public_html
  ServerName     example.net
  ServerAlias    www.example.net
</VirtualHost>

CHANGELOG
30.aug.2005 - 0.6 - changed hook for main function (ruid_uiiii) to ap_hook_head
er_parser and don't stat the file, use finfo structure to get uid/gid (if RMode
 stat)
23.oct.2004 - 0.5 - after request sgid/suid back to User and Group
11.oct.2004 - 0.4 - first release

LICENCE
ASL-2.0(Apache Software License)

Copyright 2004 by Hideo NAKAMITSU. All rights reserved
Copyright 2004 by Pavel Stano. All rights reserved

THANKS
bon for help with english ;)