There is still the old Logitech SqueezeCenter server and plenty of SquezePlayer servers/clients out there to make your whole home audio. I run a SqueezeCenter Server on my synology with all my audio tracks there, and then you just add Squeezeplayer hardware clients that act as your speaker output in each room to play individually, or synchronize multiple rooms. The hardware died in the mid 2000's, but the software never did...
These clients can be RPi's with Squeeze software, in my case, a bunch of old/repurposed android cell phones with a Squeeze Player server software, going to various old iphone speaker docks, 2.1, and 5.1 systems acquired from goodwill's around the house and connected via mic jacks. I also picked up a few chinese DLNA network players that worked ok too in this. My Pioneer Elite receiver also shows up in the inventory for room control, my buddy I setup uses his with two Onkyo's.
Wireless audio sync on my android player servers is always a problem with delay differences between rooms, but if wired, it works just fine.
There are various player clients for choosing tracks from your library and control, ala sync across devices. I had to buy one for my ipad, but plenty free on android, and better ones less free. You can even control via the web ui on the server, in my case my Synology.
HTH!
-mb