The '''Filesystem Hierarchy Standard''' is a standard that describes the organisation of files and directories on [UNIX]-like operating systems. 
Its home is: http://www.pathname.com/fhs/

If you've ever wondered about why there are `/bin`, `/usr/bin`, `/usr/local/bin` etc., then this is the place to look.

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Notable points of [Tcl]/[Tk] interest in this standard are:
   * [tclsh], [wish], and [expect] must be in `/usr/bin` (or must in `/usr/bin` have a link so named to the actual executable), if installed.

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