ive been using kodi (xbmc was better moniker) since google killed sagetv. i recall attempting plex, but it seemed to lack some open/extensibility (its been awhile).
i have a side project i want to make as a modular plugin generating a cable layout with original air orders and networks/channels… kodi seems most optimal, but ill admit its been a long while since i looked at plex.
so why plex over kodi?
I believe that Kodi, Emby, and Plex are all forks of XBMC… Not sure about Jellyfin but it wouldn't surprise me to find that it also was.
Plex originally was a fork of XBMC for MacOSX and had the name OSXBMC, but I doubt they nowadays use a lot of code from XBMC
Kodi is the new name of XBMC
Jellyfin is a fork of Emby, but Emby isn't a fork of Kodi/XBMC. It's even written in a completely different language. People were mad that Emby went closed source, so they forked the latest open source code and called it Jellyfin.
Interesting… I was confident that Emby was an XMBC fork but it looks like you're right.