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.
PyTioga is for creating figures and plots with high quality text and graphics in PDF format. Text is processed directly by TeX (not an emulation), and the graphics covers a broad range of PDF features including images, curves, clipping, and transparency.