ecu: Extended Call Utility (ECU) is a research and engineering asynchronous serial and telnet communications program, originally for SCO UNIX V.3.2/386 and XENIX V/286 systems.

yam: YAM (Yet Another Modem Program) 3.13, the classic CP/M communications utility

rt11-modem: DECUS RT11-MODEM (15-Aug-1984)

seyon: Seyon is a complete full-featured UNIX telecommunications package for the X Window System

ncsa-telnet-dos: NCSA Telnet for MS-DOS (and compatible) systems

uckermit: μC‑Kermit (μCKermit, micro‑C‑Kermit, microkermit) is a minimalistic Kermit implementation for small, embedded, or resource constrained systems (CP/M, PDP‑11, etc.)

ms-kermit: MS-DOS Kermit

bnu-hdb-uucp: BNU (Basic Network Utilities) / HDB (HoneyDanBer) UUCP