I want to stream mkv files to Android, iOS, Mac, and Windows. Transcoding isn’t that important. Just want something convenient.
For the widest device coverage, Plex is probably your best bet. I run a Plex server and can watch from anywhere on our network because they have apps on everything.
An alternative would be Jellyfin. I haven’t used it myself but have heard nothing but good things. I’m just not sure how device coverage is.
Do you need it to stream simultaneously or are you okay with it streaming async? If the second, any common media server software should do you well, take a look at things DLNA compatible. That should stream to VLC easy for any workstation/phone and it supported by most smart tvs/media boxes.
If simultaneous, maybe something like obs studio could work?