"You could call them the "Little 4," a play on the "Big 4"
systems management companies: BMC, CA Technologies, HP, and
IBM.
"The Little 4 may be smaller in terms of their bottom lines, but
in terms of systems management capabilities, there's nothing little
about the open source offerings from Zenoss, Hyperic, GroundWork
Open Source, and The OpenNMS Group.
"This is a biosphere within the open source ecosystem that has
seen a lot of flux in the past few years. In 2006, Zenoss was one
of six vendors (the others being Ayamon, Emu Software, Qlusters,
Symbiot, and Webmin) that launched the Open Management Consortium
(OMC), "an effort to promote the adoption, development, and
integration of systems and network management software based on
open source and open standards technologies."