FileInfo.com - The File Extensions Resource

.BOK File Extension

File Type 1	TestGen Testbank File (Most common)
File Format	File
Common?	No
File Description	Compressed "book" of questions for creating tests with TestGen; used by teachers and other educational instructors; often included on CDs that come with textbooks published by Pearson Education; may also be downloaded from the Internet.
Program(s) that open bok files	Mac / Windows: Pearson Education TestGen

File Type 2	ProStores Dynamic Web Page
File Format	Proprietary File
Common?	No
File Description	Web page created by ProStores, a Web-based e-commerce platform supported by eBay; may include dynamic content generated from information stored in a ProStores database. Examples of filenames used by ProStores Web pages include "StoreFront.bok" and "Cart.bok;" they may also be followed by one or more parameters, such as "Page.bok?file=test.htm."
Program(s) that open bok files	Mac / Windows: Edit with eBay ProStores; View in a Web browser

Information from FileInfo.com - The File Extensions Resource.
http://www.fileinfo.com/extension/bok