ATLANTIS  [client]
A macOS-only client, long-lived and long in beta. Its scripting is documented as
no longer working, which is the one honest "no" in this section.
https://www.riverdark.net/atlantis/
Runs on: macOS

Capabilities
  Read off each project's own documentation, not measured by us — a client has
  no handshake for us to observe. "unknown" means we looked and did not
  establish it. It never means no.

  screen reader    unknown
  TLS              yes
      https://www.riverdark.net/atlantis/history.php
  UTF-8            yes
      https://www.riverdark.net/atlantis/history.php
  MCCP             yes
      https://www.riverdark.net/atlantis/history.php
  GMCP             unknown
  MSDP             unknown
  ATCP             unknown
  MXP              unknown
  MSP              unknown
  scripting        no
      https://www.riverdark.net/atlantis/

  6 of 10 rows are unknown: we did not find the project's own documentation
  saying either way. A short honest table beats a long guessed one.

Atlantis is a native macOS client that has been around since Mac OS X 10.3 and
was updated for 64-bit in the Catalina era. It handles RFC 2066 character-set
negotiation and Unicode, which is better than its age would suggest, and it does
MCCP and SSL.

THE ONE "NO" IN THIS SECTION

Its scripting was Perl, through the CamelBones bridge, and the project's own
home page says it no longer works — Apple's handling of Perl changed and the
library's author died some years ago. That is a sourced absence, which is a
different thing from an unknown, and it is the only cell in the whole client
section that carries one. Everywhere else the honest answer was that we could
not establish it.

EVERYTHING WE COULD NOT ESTABLISH

The version history is complete and public and mentions MCCP, SSL and charset
negotiation — and never mentions GMCP, MSDP, ATCP or MSP. MXP appears once, as
something intended for a version after 1.0.0, which has not arrived.

There is a Perl Atlantis::Speak() call in the scripting API, and it would be
easy to read that as screen-reader support. It is not: it is a scripted
text-to-speech call in a scripting system the project says does not work.
VoiceOver, "accessible" and "screen reader" appear on none of the home page, the
downloads page, the full version history, or the archived user guide.

The current download is 0.9.9.8, still nominally a beta, with no release date
published anywhere on the site.

See also
  Mudlet — /reference/clients/mudlet
  CHARSET — /reference/protocols/charset