Check It Out
Matt has put the NW tree widget to good use, providing a tree-based interface to his netWindows CVS tree checkout. You can checkout the PHP code for it too.
One of the things Matt suggested with regards to the tree widget was an "opened" flag that determines whether or not a node that has children is expanded by default. It seems pretty obvious in retrospect, but it's a good thing Matt said something or I might never have done it. That said, support for the "opened" attribute on inline tree widget declarations is now in CVS.