What software can create OS image backups for platform independent servers

I have a couple servers for which I use the inbuilt backup tools to make OS backups, is there software that can automate the process and make similar format backups. Are there any freeware tools available, paid software will do too.

Edit:I have a couple of CentOS and Windows Server 2008 R2 servers

From serverfault rzlines

• Bacula is available for all unix-likes and Windows, and can backup in OS-native format as well as in a compatible format (tossing e.g. NTFS ACL etc.). It works great, handles also tape libraries, but is a bit tricky to configure.

  Documentation link You have to read this, because you have to understand and test your backups.

  Bacula answers on serverfault

  rzlines : @knitti any configuration guides available?

  knitti : don't know any besides bacula's own documentation
  From knitti