From Ericom Software:
PowerTerm InterConnect is a fast and effective MAC OS X terminal emulator for running legacy, host-based applications. PowerTerm InterConnect supports the broadest and widest range of hosts on the market today, including support for IBM (3270 and 5250), Compaq, Digital, Unix, Tandem, Televideo, HP, SCO, Data General and more. PowerTerm Interconnect has more state-of-the-art features and faster response capabilities than any available competing solution. Features include customizable function keys, multiple concurrent sessions, menu bar, scalable and selectable fonts, intelligent copy and paste, scripting, printing and more.