This is the main web site for the Program Library HOWTO. This HOWTO for programmers discusses how to create and use program libraries on Linux using the GNU toolset. A ``program library'' is simply a file containing compiled code (and data) that is to be incorporated later into a program; program libraries allow programs to be more modular, faster to recompile, and easier to update. Program libraries can be divided into three types: static libraries, shared libraries, and dynamically loaded (DL) libraries.