Grace (plotting tool): WYSIWYG, Operating System, Unix-like, X Window Motif (widget toolkit), OpenVMS, Linux Journal, Linux, Microsoft Windows

Motif (widget toolkit): Graphical User Interface, Widget Toolkit, X Window System, Unix, POSIX, Workstation.

XEphem: Ephemeris, Planetarium, Unix Like, Operating Systems, Motif (Widget Toolkit)

Unix/Linux operating system

Fiwix: Operating System, UNIX, Linux