The Java applet on the following page lets you connect to the IRC
and join any Undernet channel from your browser.
Probably only the second best solution, but you can find links and hints
about IRC software (IRC - clients etc.) on my IRC-Page ... :-)
Give it a minute for loading (34k) - connecting can be slow.
Before the applet starts there will be a Java-security check,
you will have to accept the certificate by clicking the accept button.
After that choose your own nick name
and type in into the light grey "Nick Name" field,
then click on "Connect Now!" to start chatting ...