NRPE

NRPE (the Nagios Remote Plugin Executor) lets Nagios run plugins on other machines. You install a small daemon on the remote server, Nagios asks it to run a check, and it sends back the result. This is mostly used for things you can't check from the outside, like disk usage.

I am the current maintainer and I handled the 4.2.0 release.

GitHub | Changelog

4.2.0 (coming soon)

Most of this release was contributed by Doug Nazar. It has a lot of cleanup in it: