How can I deploy an applet that uses native libraries?
For starters, the applet needs to be signed (see HowCanAnAppletReadFilesOnTheLocalFileSystem for details). All the gory details of how to load the native libraries needed by the applet can be handled by a helper class like the JNLPAppletLauncher. (Although that page is JOGL-centric, that class can be used for other libraries as well.) Note that you’ll have to include several libraries (for Windows, Linux, OS X etc.) if you still want cross-platform compatibility.