purty-mode.el — Safely pretty-print greek letters, mathematical symbols, or anything else.
purty-mode is a minor mode which swaps whatever-regexp-you-want for whatever-symbol-you-want on the fly. Given that the text itself is left untouched, purty-mode can safely be used when writing code or latex or org or whatever.
Either install purty-mode from a package.el archive such as MELPA, or place purty-mode.el somewhere on your load path, and add (require ‘purty-mode) to your .emacs.
M-x purty-mode invokes purdy-mode on the current buffer.
Substitutions can be added to purty via the purty-add-pair function.
(purty-add-pair ‘(“Xi” . “Ξ”))
This source is essentially an extension of Mark Trigg’s lambda-mode.el.