[lieks]

It was originally designed to be used by government software in the EU. AFAIK, it doesn't really get used for much else, but it fills a niche not covered by the GPL family, which is weak/non-viral copyleft (as the LGPL provides), plus handling SaaS in a reasonable way (as the AGPL provides).

Copyleft protects against proprietary forking, and also assures the community you can't close the source in the future. Weak/non-viral copyleft makes it so you can still link it to proprietary software, so you could sell integrations (non-LSP) or closed-source plugins.

LGPL and GPL licensed software can be provided over a network with proprietary changes. The AGPL and EUPL both close that hole. Every change to the modules covered by the EUPL must be open sourced, even in that case.

If your intention is to monetize the LSP itself, open source is probably not what you want. It's fundamental to open source that anyone can use it for any purpose, and also fork it. Permissive licenses like the MIT license allow relicensing to a proprietary license later (see Redis) but that causes problems with the community (see Redis), and is nearly guaranteed to cause a fork.