MathLib is not required for the use of PocketC. However, many floating point functions are not available if MathLib does not reside on your PalmPilot. See the library routines documentation to see which functions require MathLib. MathLib is a free shared library that can be used by any OS 2.0 Pilot program that needs IEEE 754 double precision math functions. It's distributed under the terms of the GNU General Public License, and is freely available with full source code and documentation at the MathLib Information web page. It's not a part of the PocketC program, and you're not paying anything for its use; a copy is simply included in this archive for your convenience. For more information on MathLib, see the MathLib webpage at http://www.probe.net/~rhuebner/mathlib.html