Version 6 of library

See http://www.purl.org/tcl/home/man/tcl8.5/TclCmd/library.htm for the man page for a long list of Tcl commands in a general Tcl distribution library.

"Library" means different things here, all different from the popular concept "a building with many books inside":

Tcl and Tk both are delivered as shared libraries.
In a typical distribution, there is a lib dir, which contains directories like tcl8.3 and tk8.3, which contain Tcl scripts and other packages.
A popular Tcl-only extension is Tcllib, the "Tcl library", and its young brother Tklib

Just to make things a little less unclear... RS

Category Command from Tcl