We never quite knew whether it would come to this, but yes, Minecraft 1.13 support has finally arrived in the main Overviewer branch. This was thanks to the hard work of gmcnew, RedSparr0w, jvaskonen and agrif.
You can grab the binaries as usual on our downloads page.
2019 marks the ninth year of Overviewer's long and varied history, which means that we probably have people looking at Overviewer maps now that are younger than the project itself, which is impressive! During this time, 2553 commits have been made to the repository by 108 contributors from all over the world, for which we are incredibly grateful for.
If you need help with Overviewer or just want to say hi, you can reach us on IRC or Discord. We also have a Twitter account, @mcoverviewer, if you're into that.