It works the same as when you publish any other Processing applet. The only issue that I am aware of is that if you export an applet and all the jar files for included libraries are NOT wrapped into one big jar file for the applet (like what happens when exporting an OPENGL sketch), then you will have security issues when trying to access the line-in. In the case of one fat jar, it's possible to sign that jar and get access to the line-in, but I haven't figured out yet what all needs to be signed when the jars are all separate. If you aren't trying to access the line-in, then you shouldn't need to worry about any of what I just said.