Well, what we've done seems to be working pretty well. Have an open source tool (or leverage someone else's) and then sell additional hosted or installable tool

Well, what we've done seems to be working pretty well. Have an open source tool (or leverage someone else's) and then sell additional hosted or installable tools that expand the power of the underlying tool. I know of a lot of places that do well with providing support and consulting for their open source offerings, but that doesn't scale as well as something that you can charge for on a recurring basis and that doesn't derive directly from butts in seats.