Permission to copy and distribute Interface Elements in its entirety, for non-commercial purposes, is hereby granted without fee, provided that this license information and copyright notice appears in all copies.
Note that distributing Interface Elements 'bundled' in with ANY product is considered to be a 'commercial purpose'.
This software is provided 'as-is', without any express or implied warranty. In no event will the author be held liable for any damages (direct, indirect or otherwise) arising from the use of this software. In the case of states in which such disclaimers do not apply, the author hereby limits his liability in such matters to USD $1.
You are allowed to use anything that you created with Interface Elements in commercial applications freely. If you do this, a short notice would be sufficient in the about box, like "The GUI was created with Interface Elements" or something like this.