Gnuplot for graphs. LaTeX PGF/TikZ for complicated diagrams. Lines and boxes drawn with ASCII symbols (e.g., +, -, |, <, >, ^, v, /, \, ', `, etc.) using Emac

Gnuplot for graphs. LaTeX PGF/TikZ for complicated diagrams. Lines and boxes drawn with ASCII symbols (e.g., +, -, |, <, >, ^, v, /, \, ', `, etc.) using Emacs for very simple diagrams. PGF/TikZ has considerable learning curve, so it may seem like a hassle in the initial days of learning to use it. But after mastering it once, one can unlock a lot of power and flexibility that comes with it. The PGF/TikZ manual at http://mirrors.ctan.org/graphics/pgf/base/doc/pgfmanual.pdf http://mirrors.ctan.org/graphics/pgf/base/doc/pgfmanual.pdf is really worth seeing. This manual, which is itself designed using PGF/TikZ, is a masterpiece!