From Introduction:
The Netbook of Feats is published using Wizard of the Coast’s Open Gaming License (OGL). This legal document (found in the legal section of the NBOF) protects the work in this document so that it remains free for you to use in almost any way imaginable. Basically the material in the NBOF that is designated as Open Gaming Content (OGC), which is almost everything in the NBOF, can be used in any publication, armature or professional without any restrictions, except that you must credit the original author of the work. To use our feats you needn’t pay us, or ask permission, or sign any contracts, the only thing you must do is include the OGL in any document you use the material in, and you must abide by the rules of the OGL.