TBK file is a document file used by ToolBook software, a program for creating e-learning courses and materials. TBK file structure is similar to that of a printed book, and it contains also slides in the style of Microsoft PowerPoint.

First version of ToolBook software was presented to the public in 1990, and had since recieved many updates and additional functionalities. Current verision allows user to publish TBK data in the form of web applications in DHTML format.