AquaTerm is a Mac OS X grahics renderer. It allows command line applications written in ObjC, C, FORTRAN, Lisp, Perl or Python to display vector graphics, text and images using a simple API. Adapters for gnuplot, PGPLOT, and PLplot exists as well.
Aquaterm is great but since many years now there is no active developement. It would be great to see new enhancements