Open or Not

A downloadable product reaches the user as code. A SaaS reaches the user as a result over the network, and the code never leaves the provider.

HGL acts on distribution. Everyone is free to copy and modify. Once you distribute, the whole source must be available to every user for free, under HGL, with no additional restriction. For a downloadable product, that covers every copy. No fork can close what it has to hand over.

The only case where HGL seems not to work is SaaS. A SaaS can take HGL code, change it, run it on its own servers and never share a line, because nothing was distributed.

But look at what you are building. If your product is the alternative to SaaS, code users can own, run and change themselves, then a SaaS running your code in secret is not competing with you. It is just another SaaS, the very thing your users chose to leave. It serves a market that is not yours. And the moment it wants your market, it has to give users the code. Then it distributes, HGL applies, and it is not a SaaS anymore. It has become you.

So there is nothing to worry about. The gap exists only for those who compete as SaaS. For a SaaS alternative, HGL already covers the whole market that matters.

That is why licenses that chase SaaS with extra conditions miss the point. Every condition on how the code runs, where, by whom or for how much is a restriction on users. If you want to restrict users, one way or the other, there is no point in thinking about open source at all. Open source is giving users the same rights you have. Choose closed, and be honest about it, or choose open, and give everything. Anything in between is a closed product wearing an open name.