Core is open source, (enterprise) features remain closed source

[jayfk]

Nginx Inc. the company behind nginx is using a model like this. Nginx is free and open source, but they offer a pro version called Nginx Plus to fund development. The Plus version is subscription based and targeted to enterprise customers.

[freakboy3742]

A problem with this approach is that the enterprise features don't get the engineering benefit of being open source - more eyeballs on bugs, etc.

A variation on this theme is to hold back features from the open source version until a certain time passes. Aladdin Ghostscript did this for a while - if you wanted the latest, greatest code, pay us; otherwise, wait 6-12 months and get it in the open source pool.

[lukego]

This is an exclusive model: it helps one company make money on the project but not others.

[thbar]

An instance of this model is Sidekiq by @mperham (maybe Mike you'll want to share more about your experience here?). I think Mike's Inspektor Pro is open-source too, by the way (a different model).

[nanuxbe]

+1 on the main idea

[mperham]

Yep, I sell closed-source extensions to Sidekiq's open core as my full-time job. The source is actually available (it is normally packaged Ruby code) but not without payment.

[wolftune]

This is not a model for software freedom, it's a model for half-assed freemium software freedom. At best, it's like GitLab where the extra features are really not that significant a set, but still this is a symptom of the funding problem, not a solution to it.

[cvrebert]

There's also the issue of what happens if someone from the community tries to contribute their own implementation of an Enterprise™ feature to the open-source version.