FTP Library Package for Tcl/Tk - Provides client side of the File Transfer Protocol (FTP). - http://tcllib.sourceforge.net/doc/ftp-docs/
Apache Tcl - mod_dtcl - An Open Source implementation of server parsed Tcl, running under Apache. It allows you to tightly integrate HTML with Tcl. - http://tcl.apache.org/mod_dtcl/
The Zircon X11 IRC Client - A X Window interface to internet relay chat written in Tcl/Tk and using the native network communications of Tcl. - http://catless.ncl.ac.uk/Programs/Zircon/
WWW Tools and Utilities - Tcl-based web servers, applets, and other assorted tools. - http://www.demailly.com/~dl/wwwtools.html
cgi.tcl - CGI support library for Tcl programmers supporting forms, tables, cookies, file upload, plug-ins, JavaScript, Netscape extensions, and debugging and handling CGI errors. - http://expect.nist.gov/cgi.tcl/