historically there was an applet that ran in your browser but nowadays this is considered
deprecated so there are some other possibilities left to get connected to dn42 (pick any):

• download rtr.jar and online-sw.txt and type "java -jar rtr.jar routercw online-" in a terminal (you should use the popup window)
• if you hate jvm and prefer native linux binaries then please visit portable
• type "telnet sandbox.freertr.org" in a terminal to get to a sandbox
• type "ssh sandbox.freertr.org" in a terminal (any user/pass will do)
• ftelnet is a 3rd party webapp that connects you there from your browser
• point your vnc client to sandbox.freertr.org:5995
• point your modem to sip:42@sandbox.freertr.org
• point your xot to sandbox.freertr.org