Basically, we wanted to! We've benefited hugely from open source projects ourselves, and have always enjoyed being part of the community surrounding them. It seems like the default state is to not be open source, but we realised that since we own and run the business behind ShareLaTeX, we had the freedom to play by our own rules. We also think it makes sense from a business point of view as well, since it will (hopefully) make us accessible to a wider audience, particularly onsite installations that we don't have the resources to support as a proprietary 'enterprise' system.
I (and I suspect many others here) would be very interested to know what effect this will have on your turnover. I guess you will get some increased revenue as others have indicated in this thread, but also loose some for those who just fire up their own installation.
Presumably you won't really know until your try it, but do you have any data to support that it might increase your revenue (assuming of course that is a goal here - rather than just growth of the number of users of your software - I realise that the two can go hand-in-hand!).
We don't have any hard data - this is based on our personal vision, and our understanding of our user base. People mostly use ShareLaTeX because: 1) There is no installation, 2) You can access it anywhere, 3) You can collaborate easily and effectively without needing to be technical and know git/svn/etc. I don't think being open source will threaten any of those points, but it will make ShareLaTeX accessible to the large group of people who want to run a local version but haven't been able to so far.
It will be interesting to see how things look in a months time. I'll try to post an update!
Please do post an update. I have a side project I'm starting that will be a paid service, but I'd like to AGPL it in keeping with the free software philosophy.
