Soiled is a Flash-based telnet client and terminal emulator, supporting both char-by-char and line-by-line mode. In line-by-line mode, it has some features that make it suitable for MUDs, such as aliases, macros, and hotkeys. Since it is implemented in Flash, it can be used from a Web browser.
Qodem is a re-implementation of the Qmodem DOS shareware communications package, updated for more modern uses. Major features include Unicode support, scrollback buffer, capture file, screen dump, dialing directory, keyboard macros, script support, Xmodem, Ymodem, Zmodem, and Kermit. It can connect over serial port, telnet, ssh, rlogin, and command line, and supports multiple terminal emulations including ANSI.SYS, Avatar, VT100/102, VT220, and Linux.