File::Map maps files or anonymous memory into perl variables.

Advantages of memory mapping
* * Unlike normal perl variables, mapped memory is (usually) shared
between threads or forked processes.

* * It is an efficient way to slurp an entire file. Unlike for example
the File::Slurp manpage, this module returns almost immediately,
loading the pages lazily on access. This means you only 'pay' for the
parts of the file you actually use.