KST2Mac — native ON4KST chat client for macOS

Native macOS client for the ON4KST chats — the DX-liaison chats VHF, UHF and microwave operators keep open beside the radio during a lift or a contest. Any number of rooms at once, each pane holding its own login, room picker, station list and message box, and each able to be torn out into its own window without dropping its connection. Station list carries name, locator, and QRB/QTF worked from your own square, with away stations marked.

Message traffic is coloured by what it is: a stable per-callsign hue that reads the same in the log and the table, and KST2Me's own highlight conventions for /CQ, preamble and watched callsigns, so an operator who knows one client can read the other. Grid squares and frequencies are picked out inside message text. Alert sounds fire whether or not the app is in front — the case a notification banner cannot cover — and mentions raise a banner when it is not.

A built-in DX-cluster node re-serves the chat's spots on a LAN port, so DXCA or any cluster client dials it as one more node and receives them verbatim, unparsed. The whole telnet protocol was reverse-engineered from packet captures of the live service rather than from documentation, which turned out to be wrong about the room list, the timestamp format, the command rate limit and more; docs/PROTOCOL.md in the repo records what is captured versus what is still inferred. Universal binary (Apple Silicon + Intel), Developer-ID signed and Apple-notarised.

Named after and modelled on KST2Me by Bo OZ2M, the long-standing Windows client; the protocol work here is original, but the interaction design and the highlight conventions follow OZ2M's manual.