The title of this post is "Loops - short form video wtih ActivityPub - is now open source!"

To mean they've published the source code to the public. Reading further, I see "First alpha release" a couple times, meaning the project is in its very early stages and is just now in a state where the developer can upload it to Github for access by the public.

Viewing said Github repository, I find it is licensed under the AGPL, a strongly copyleft license. This software will be free to use, distribute, examine and modify forever under those terms. Looks like the intention here is for the software to be Stallman-style "Free."

So you have apparently pissed your panties at the mere usage of the words "open source" in which case I'm not even going to bother to try telling you to go touch grass. You're too far gone.