Security is a major topic of conversation within the Java Community.
Obviously the automatic downloading of untrusted programs has the potential for
abuse. Java was designed to prevent a downloaded applet from doing any damage to
your computer. The principle limitations are that an applet cannot access the
file system in any way, and it can only contact the server from which it was
run. Unfortunately, this limits the cool stuff you can do with Java. For
example, there are several sites on the net that provide dynamic maps, it would
be great to use these as a map source with javAPRS, but the security manager
prevents this. It also means you can't connect to two different live servers and
display the data in a browser.
The JDK allows this security to be turned off, however so far the browsers do
not. As you are writing your page, keep this in mind. All the data must reside
in a single network server if you want it to be viewable in a browser. You can
run the applet locally with the Open File... command, but again, all data must
then be on the local file system, and you must use local references to the data
javAPRS is now distributed as a signed applet. This allows access to
off-site network ports and web sites. This allows javAPRS to be hosted on
a web server completely separate from the APRS Internet network and maps can now
be retrieved directly from Tiger and Mapblast. A list of available servers
is at APRS Servers.