The Notebook Format
Notebooks are interactive documents which combine text, equations, graphics, and sounds in a single platform-independent file format.
Notebooks are ideally suited for the creation of professional-quality technical documents. They can be readily optimized for both print and electronic publication.
Notebooks can also include interactive elements like hyperlinks, buttons, and palettes. Hyperlinks will work in MathReader. However, buttons and palettes require a complete Mathematica front end.
Notebooks are saved as plain ASCII text files rather than in binary format. This makes them easily portable—they can be transmitted by email or by FTP in text mode and shared by users on different computer platforms. They can also be made available for downloading over the web. The notebook format is denoted by the extension .nb.
Mathematica notebooks look and work the same on Windows, Unix, and Macintosh computers.