ZTerm
ZTerm is a shareware terminal emulator for Apple Macintosh computer systems. It was introduced in 1992 running on Macintosh Operating System 7 and has been updated to run on the latest version of Mac OS X. Its name comes from its use of the Zmodem file transfer protocol, which ZTerm implemented in a particularly high-performance package. Contrary to the OS X built-in Terminal, which only communicates with other programs, ZTerm only communicates with hardware serial ports.
Read more about Zterm.