This small calculator app is ported to eFLTK.
It's based on flCalc - Copyright 2000 by Yves Usson. 

<snip>
The scientific calculator for the FLE desktop environment
flCalc is a small program emulating a pocket calculator. 
It is rewritten from a program by Mark Overmars (author of the old FORMS library) 
and using code written by Robin Humble. 

http://www-timc.imag.fr/Yves.Usson/personnel/mysofts.html
</snip>

Mikko Lahteenmaki