We now have a Stand Alone Jar version available
instead of the increasingly illegal and difficult Java Applet:

1) You download this: http://www.seaice.dk/dtuseaicebrowser/dtuseaicebrowser.jar (approx 110000 bytes)
2) Run it with: java -jar dtuseaicebrowser.jar
3) Then select 'N' or 'S' and 'synconline' and is should work as usual.

'open file' can be used to add local vectors of your own design

It can also be used offline with date-ordered local files in the same catalog 2015/01/20/...

The default off-line layers can be had from:
http://www.seaice.dk/dtuseaicebrowser/NorthLayers.zip or: http://www.seaice.dk/dtuseaicebrowser/SouthLayers.zip
You extract those in the jar catalog as well.

Old info below!
In the case the Applet wont run, this might help you:

1) Check your Java Version
2) if you need to upgrade do so
3) Open the Java Control Panel/Configuration Tool and go to the 'Security' tab:

Press the 'Edit Site List...' button and add 'http://www.seaice.dk' to the Exception Site List.
Press 'OK' (*not* 'Add' again) to save it.
Make sure you accept all the inherent security risks...

If you have any questions, don't hesitate to contact: rs@space.dtu.dk