This tutorial describes how you can use Netbeans to edit and compille compile drivers, and then load them into JAS3 to run them. The advantage of using Netbeans to do this, as opposed to the editor built-in to JAS3, is that you can get code completion, syntax highlighting etc.
...
To execute a custom goal select the org.lcsim project, from the popup menu select "Execute Custom Goal", "More Goals...", then from the dialog choose "jar:install" and then "jas:install".
Selecting the toggle "Add to Favorite Goals" will make repeating this in future easier.
...