"During 2008 it became clear that the open core approach - in
which the core software is open source while an enterprise version
is also available with proprietary extensions - has many benefits
for vendors of open source software, including providing up-front
revenue and in balancing the requirements of community and
enterprise users.
"Proprietary vendors tapping into the benefits of open source
development tend to generate revenue from other products or embed
open source within larger commercial products, rather than building
proprietary extensions on top of open source (think of IBM's use of
Apache within WebSphere)."
