License:

Default Icon by interactivemania is licensed under a Creative Commons Attribution-No Derivative Works 3.0 .

This means in short terms, it allows you redistribution, commercial and non-commercial, as long as it is passed along unchanged and in whole, with credit to interactivemania. For further info or a more specific license don't hesitate to contact us at: info (at) defaulticon.com.
A License clarification: The license that accompany the icon set is CC Attribution-No-Derivatives. This means the following: You can use any part of the set for your UI Design, Web site design, mobile application design, desktop application design/UI,theme design, commercial or not, without any further clarification, with only obligation to attribute interactivemania, in the credits page. The No-Derivatives directive forbids you to build a new icon-set, upon DefaultIcon. It doesn't forbids you to build any of the afformentioned projects using the set.