Please read the release notes at https://github.com/JoinMarket-Org/joinmarket-clientserver/blob/master/docs/release-notes/release-notes-0.9.4.md for details on what this release includes.
This release (1) fixes a potential crash vector for makers, if an unexpected message format is sent over the wire, (2) allows users to make custom labels for their addresses, and (3) adds a non-default fourth IRC server (update your config); see release notes for details on these three things.
A windows binary (.exe) is provided, as usual.