GNU M4 - GNU M4 is an implementation of the m4 macro preprocessor.
Hackr.io - There are tons of online programming courses and tutorials, but it's never easy to find the best one. Try Hackr.io to find the best online courses submitted & voted by the programming community.
PP - A generic Preprocessor - P is a text preprocessor designed for Pandoc (and more generally Markdown and reStructuredText).
Google's Python Class - Assorted educational materials provided by Google.
GPP - GPP is a general-purpose preprocessor with customizable syntax, suitable for a wide range of...
A Byte of Python - A Byte of Python is a Python programming tutorial and learning book that teaches you how to program with the Python programming language.