Geodesy based library (geodetic and geocentric functions)
geoStarsLib has functions for dealing with many geodesy-based problems found in positioning, pointing, and surveying situations. It is useful to determine absolute position on the earth, pointing vectors, coordinate transformations, and other functions.
CAVOR is an engine for building apps that involve both graphic and text/numeric data. Primarily GIS is the initial focus, but consider also CAD, CASE, project management (eg PERT charts), and others. Built-in scripting, C API, also supports Tcl and Java.