I've found the Photoshop File Format Specs at: http://www.adobe.com/devnet-apps/photoshop/fileformatashtml
But unfortunately they don't include the Brushes (abr) file format.
Also, the SDK FAQ references a form you are supposed to fill to ask for this, but there's no such a form anymore.
Where can I find information about this?
Thanks in advance
Europe, Middle East and Africa