>>415
ソース見ろ。

mate-calc
https://github.com/mate-desktop/mate-calc/blob/master/AUTHORS
> MATE:
> Perberos
> Steve Zesch
> Stefano Karapetsas
>
> GNOME:
> Glade support/Main maintainer: Robert Ancell
> Original author/maintainer: Rich Burridge
> Arithmetic precedence support: Sami Pietila