============COMPATIBLE ALSO WITH GIMP!==============
[Please don't ask me to make a PTSAI version, they are two different brush setting system, they can't be similar in either software and I don't know how it works in PTSAI]
============================HOW CAN I USE THEM IN PHOTOSHOP?=====================================
1) Just extract the zip file wherever you want to.
2) Open your PS work.
3) Go to the selection of brushes with right-click or on the menu-bar to the top and click on the arrow to the right.
4) Click on "Open Brush..." and search your file, the brush will appear in the brush list.
(You can put them also in the "C: Program Files (x86)Adobe/Adobe Photoshop CS5/Presets/Brushes" folder and you'll find them in the standard brush list when you'll click on the arrow)
============================HOW CAN I USE THEM IN GIMP?==========================================
for this update!
1) Just extract the .abr file of the ZIP in the folder "C: Program Files (x86)GIMP/Brushes".
2) Open your GIMP and it will works!.