I use GIMP and find GURM works extremely well for organizing and using my brushes. The only thing I can’t do with it is use sub-folders under a general category. I usually make a general category, like smoke and put all my smoke brushes in that category. When I want to use smoke brushes, I run the GURM filter and load up the smoke brushes. The only brushes that load automatically each time I open GIMP are the basic brushes that come with it. You can get GURM here: http://registry.gimp.org/node/13473
