This is also a placeholder page and will have more information eventually.
BetterTelnet is a Telnet client for Mac OS prior to X (7/8/9), based upon the final release of the classic NCSA Telnet. The final BetterTelnet release is 2.0fc1. Jean-Pierre Stierlin maintained MacSSH for some time after BetterTelnet development ceased, and most users who happen to be stuck on a Mac OS 7/8/9 machine should probably look there instead. This page may eventually have some updates for MacSSH.
I (Rolf) don't support legacy BetterTelnet in any way at this time. The only reason you would want to use it is that it uses somewhat less memory than MacSSH when a lot of scrollback lines are stored. You can work around this issue in MacSSH by turning off "Store attributes in scrollback" in the terminal settings. However, for historical interest, the BetterTelnet downloads are below.
BetterTelnet 2.0fc1, final version, FAT (68k and PPC combined binary)
BetterTelnet source code, licensed as free software under the GNU GPL
MacBinary II+ (may be necessary to unpack the other archives with an old version of StuffIt Expander).
BetterTelnet manual and extras from the old 1.2.2 version
Old and even older terminfo definitions for BetterTelnet.
Other documentation: Release Notes - Kerberos info - AppleScript notes