rrd-fixpeaks removes errant "peaks" in RRD data. It requires rrdtool.
statsd-go is a reimplementation of statsd in Go (forked from gographite) with Ganglia submission support.
statsd-c is a reimplementation of Etsy's famous/infamous "statsd" in C.
rrd-merge merges RRD (round robin database) files together, including the files used by Ganglia, Cacti, and other rrdtool-based software.
An SMS gateway to XMPP daemon
A .NET assembly, COM component, and Ruby extension for finite element results post-processing.