As a Content Management System developer, having a good tree plugin is key to organizing files in directories. With a small number of folders, any jQuery tree plugin will suffice. But, I’ve encountered some limitations with 1000+ folders and Internet Explorer compatibility.
jQuery Tree Control
jQuery-Tree-Control is a great option for a lightweight jQuery tree script. Excellent cross-browser compatibility, small footprint, and easy to implement. The major limitation is persistence, so it doesn’t save the last folder open on refresh. I originally used this plugin for my project, but needed a few more features that the other two plugins have.