https://cabal.chat/ https://cabal.chat/ is a good program. It does not support all of slack's features, but is truly peer-to-peer so there's no central points o

https://cabal.chat/ https://cabal.chat/ is a good program. It does not support all of slack's features, but is truly peer-to-peer so there's no central points of failure or servers that can go down. (Well, I suppose if they released a buggy version of the software and you updated, that's a central source, but that's true of most software.)