https://gajim.org/ tends to be best for desktop (binaries exist for most desktop OSes).
For macOS, you may want to try Adium or Psi. Or you can use https://movim.eu/ which, though a web client, has fairly good feature support as well.
For macOS, you may want to try Adium or Psi. Or you can use https://movim.eu/ which, though a web client, has fairly good feature support as well.