I can't speak for everyone obviously, and the pure-SaaS model is definitely popular at the moment, so I'd imagine there is still a market without open sourcing

I can't speak for everyone obviously, and the pure-SaaS model is definitely popular at the moment, so I'd imagine there is still a market without open sourcing the whole thing. Having said that, I still think open sourcing it will be a net positive for you. Regardless of whatever unique client-side logic your product handles, there are numerous other static-site generators available, that are open source (heck, I'm writing one myself). In this scenario, I believe that being closed, and a service (as opposed to say a closed source, but self-hosted tool) can lose you some potential customers. I don't think being open (and thus self-hostable) will lose you any actual paying customers - those who are able and willing to self-host it are probably unlikely to have paid for a closed service in such an active (in terms of competing products/projects) niche. > I'm not sure how much of the tool itself I could open source (I've never done that) Regarding this specifically, the key thing here is going to be what (if any) libraries/frameworks you're using. Assuming you're not using any commercial libraries, it's probably mostly about making sure the various licences of the libraries are compatible with whatever license you choose to use.