"This list doesn't include projects that simply request
donations or those that make money only by selling hats, T-shirts
and other gear emblazoned with their logo. We also left off
projects that offered paid support as an afterthought or those with
support and services available only from third parties.
"Why put together a list of commercial open source projects at
all? Many businesses find it preferable to acquire software under a
commercial license because they are worried about some of the legal
provisions of some open source licenses, particularly the GPL. In
addition, many companies want reliable support and maintenance for
their software and are willing to pay for it.
"Home users are much less likely to pay for open source
software, and as a result, the vast majority of the projects on
this list are aimed at businesses rather than home users."