NetPlug is an extensible multi-connections, multi-protocol, network client program, written in pure Tcl/Tk (and thus running on all platforms Tcl/Tk runs on, ie most Unixes, PCs (Win3.1,Win95, WinNT) and Macs (both PPC and 68k))
The successor to tkconnect (no longer available).
Simple Tcl7.5/Tk 4.1 TCP/IP multi-connection, multi-window client that could be useful for MUDs, game servers, debugging a network, etc. but mainly is useful as an example/tutorial on using Tcl/Tk networking and basic widgets.