A large number of library modules are distributed with the Erlang runtime system. It always pays to spend some time reviewing what is available and making a mental note of the library modules that might contain functionality you might find useful. In between releases, it makes sense to read the release notes, which contain the major changes you should be aware of in the libraries, as well as provide pointers to new modules. If you cannot find a module providing you with a generic solution to your problem, you should search for it in the open source community, as the chance that someone has written and released it under a friendly open source license is good. This section deals with the most commonly used libraries in Erlang systems. But before looking at these libraries, let’s look at how you access the documentation associated with them.
The Erlang distribution comes with documentation, available in both HTML and Unix manpage formats. It is often bundled with the Erlang release, but can also be downloaded separately or accessed online at http://erlang.org (see Figure 3-1). You can access the root page of the HTML documentation by opening the file:///<erl_root_dir>/doc/index.html page, where the doc subdirectory is located in the root directory of the Erlang installation. In Windows, a shortcut to the documentation is included in the Erlang/OTP installation directory within the Program Files menu.
If you are using a Unix-based system,