Overleaf isn't fully open source either, since they have a paid tier with features which are not present in this repo. Inline commenting for example, is a Server Pro -only feature.

The Typst web app, which is similar to Overleaf, is closed source. Overleaf itself is open source, yes.

Read your own link before posting. While the parent was wrong about it being fully closed source the Overleaf editor isn't fully open source either, it is open core under AGPL.

> If you want help installing and maintaining Overleaf in your lab or workplace, we offer an officially supported version called Overleaf Server Pro. It also includes more features for security (SSO with LDAP or SAML), administration and collaboration (e.g. tracked changes). Find out more!

"That" in my sentence meant that Typst web app is closed source.

But that doesn’t make much sense - by your account Latex would also be a mix of closed and open source, since closed source web apps exists for writing Latex.

What does not make sense? Did you mean to answer to someone else? I only stated that Typst (the typesetting engine) is free to use and modify, and only the web app is closed source. Typst can be used without touching any web apps. I use Typst locally.

I made no claims about any mixes or claims about LaTeX.