Telnet

Georgia SoftWorks Telnet Server
Supports data stream encryption and network enabled DOS legacy applications. Windows specific, with video color options.
http://www.georgiasoftworks.com/

Poor Woman's Telnet Server
A standalone Java server based upon telnetd and compatible with Unix and Windows. Licensed under the GNU GPL, this is free software.
http://pwts.sourceforge.net/

telnetd2
Presents this free, open source embeddable Telnet daemon written in Java. Includes a forum, a mailing-list and documentation.
http://telnetd.sourceforge.net/