Well this product uses the JQuery Dynatree package to generate tree widgets. At first I was disappointed that it used Plone. Then I realized it was for trees of Text Strings, rather than trees of objects with names. I could be wrong on that. It says the license is some simple license, but the setup.py says it is GPL. Duh. If it is Plone Centric, then it has to be GPL. So I chose not to use it.
Fancy Tree has all the features that I need. It can handle 10K node trees, has a search box, and displays single spacing. Perfect. So I will be using it. Sadly it has too many features, but the simpler libraries do not have the features taht I need, so fancytree for me. But I do worry that it is too complex.
JSTRee looks great. Does everything I need and nothing else. Single spacing. Fancy tree was too fancy.
PrivaCV.com is currently using treeview. But it has two problems. One is double spacing,it takes up too much screen space. The more serious problem is that it is not based on JSON, works on the whole dom, so takes too much resources.