SystemTap is a higher level abstraction built on Kprobes. For more information about how Kprobes work, you can read my technical article on LWN.
As Alex mentioned, Systemtap is essentially solving the same problem as dtrace, except that it's somewhat slower (you may not perceive it to be so, depending upon what you're trying to do with it) than dtrace and not quite as polished or safe to use.
To install SystemTap SDT development package, try:
yum install systemtap-sdt-devel
