I'm just now seeing if the collaborative wiki calendar platform I've created could be used by other groups. I've made a platform where anyone can sign up for a calendar at https://hasacalendar.co.uk/ and Open Sourced the engine at http://ican.openacalendar.org/ This side of it has very little income currently. The next big task to do is redo the home page to make clearer what it does and work on the design, this side of things is not my strong point. :-/
I decided to Open Source it just because in the end that is what I'd rather do. There are a lot of pluses and minuses each way that are hard to compare, but both Open Source and Closed Source are a lot of work and as I'm doing the work I may as well have it the way I prefer. It already has it's first Open Source install, a live Jazz music calendar.