The tree menu is a project in constant development as new features are requested and bugs are identified and fixed. To ease the work the menu has a project page on SourceForge. Available there are useful development tools like trackers for bugs, feature requests and patches, a development mailing list and access to the CVS repository for those who want to have a look at the latest development code. Here's some more information about two of those, the CVS repository and the mailing list:
Development versions of the Tree Menu are kept in the CVS repository on SourceForge. Currently I'm the only developer on the project, so the code is only updated whenever I have something ready that's useful enough for people to test. Currently you'll find that new versions are coming at a pace of about two a week. Some times it's features added, some times it's bugs that are fixed.
Now you might be asking "Well, that sounds nice, but how do I get access to it?". Head on over to the project home page and follow the link "CVS Repository". There you'll find information about checking out a version from the repository, if you're comfortable with CVS tools. If you're not you can also browse the repository and from there choose to download single files.
Keep in mind that the CVS repository contains a development version. It may or may not be stable, it may or may not support specific features, and it most certainly will contain bugs. It's therefore not guaranteed that you can try out a development version without experiencing problems.
There's also a mailing list available from SourceForge. It's available through the "Mailing Lists" link on the project home page. I post a changelog to the mailing list whenever I have checked in a new version to the CVS repository, and I also post development concerns when I have something that I'd like others to look at. My hope is that the list will be useful for those who wish to take part in development, discuss the implementation of features, fixing of bugs, ideas, code, etc.