Austern has made explicit that which is implicit in other texts. Second, I like to read in places far away from my machines, and a book is still the most portable device. With the balmy Virginia weather we've been having lately, I'd rather retreat to the shade of a tree and pencil in marginalia. The book doesn't come with an accompanying CD-ROM or disk. The text is divided into three parts, with an appendix.
Models are what show up in programs.
Given Austern's 80-page explanation of concepts and requirements, the models are much easier to understand. The simple graphics also help. Collect them, and you have a snapshot of STL on a single sheet of paper. Part 2 is a formal documentation of the concepts presented in Part 1, and Part 3 documents the STL interface. The appendix addresses portability and standardization, which is still a necessary concern, because compilers are not equivalent.