"Companies that provide third-party support for open-source
software can be divided into two groups, roughly speaking.
"In the first group are what could be called 'professional
services companies'--those vendors who provide support for a
specific platform. An example is Progeny, which now patches the
versions of Red Hat the leading Linux vendor no longer
"The second group is comprised of management companies--firms
that build software to administer the open-source stack. An example
is Covelent, which builds an application that provides a user
interface to manage the full stack of open-source programs..."