Qodem is a a terminal emulator that resembles the BBS-era Qmodem. Includes phonebook, scrollback, capture, X/Y/Zmodem, Kermit, ANSI (+ music) / Avatar / VT102 / Linux emulation, Unicode, and keyboard macros. Connects over serial, ssh, telnet, rlogin.
Luit is a filter that can be run between an arbitrary application and a UTF-8 terminal emulator. It will convert application output from the locale's encoding into UTF-8, and convert terminal input from UTF-8 into the locale's encoding. It is mainly used to support xterm.
The swiss army chainsaw of terminal emulators
Extraterm is an open source project to build a terminal emulator and expand it with new features to support modern workflows and do more than just act like a glorified teletype.