A Wyatt application generally consists of a toplevel module of
application code sitting atop a numer of layers of library code:

5- application main loop and procedural code (executable scripts)
   - emplim, persim, etc.

4- application specific routines you may create (applib)
   - shiptool
   - inventory
   - prd

3- site specific routines: (sitelib)
   - customize domains, phone numbers, interfaces, etc.

2- Graphical widgets and helper routines: (wylib)
   - dbe, dbp
   - sizers
   - graphing

1- Non-graphical routines: (wylib)
   - database access
   - date/time functions
   - command line parsers

0- Lower layers
   - Tk
   - Tcl
   - BLT
   - Postgres
   - OS (Linux)
