This proposal seems to provide a nice solution on how to integrate the
lib/ext mechanism with Java Web Start. The idea of letting Javaws creating
the private lib/ext for each application seems to be very sound.
The exact syntax for supporting this still needs to be finalized. Another
alternative (prevously discussed by the engineering group) was to include
an <ext-resources> element for this, along with a <endorsed-resources> element
for support the endores API override mechanism.
This seems to be a very promising feature to include into the next version of