Use, study and develop advanced digital halftoning algorithms with Halftone Laboratory, a GIMP plug-in backed by a highly modular and extensible library. It uses .NET/Mono and GIMP#.
A tool, that converts PS files, generated by LaTeX-dvips in a way,
you can print directly an DIN A5 booklet. psheft puts 2 A5 pages on each front-
and backside of an A4 sheet. For pictures psheft can generate a postscript
halftone dictionary.