A Web ssh/telnet client

Maybe Shell in a Box, Gate One or Commando do what you want, but you might need to configure them to disable encryption:

Shell In A Box implements a web server that can export arbitrary command line tools to a web based terminal emulator. This emulator is accessible to any JavaScript and CSS enabled web browser and does not require any additional browser plugins. Most typically, login shells would be exported this way:

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Gate One™ is a web-based Terminal Emulator and SSH client that brings the power of the command line to the web. It requires no browser plugins and is built on top of a powerful plugin system that allows every aspect of its appearance and functionality to be customized.

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Commando.io is a web-based interface for streamlining the use of SSH for deployments and system administration tasks across groups of remote servers.