Pillar is the official documentation system of Pharo. It uses syntax similar to markdown which make it simple and easy to learn. However Pillars power and flexibility goes far beyond that because it leverages Latex , epecially for generating PDFs ( every PDF you have seen read for Pharo uses Latex and Pillar, except a few that use only Latex) or using advanced features like math notations , more precise image locations etc.
However can be tricky to learn, Packt publishing is a website that sells online ebooks and videos , they also offer a free ebook each day. Today they offer a free beginner guide for Latex. Offer expires in 9 hours and 45 minutes, so get it now that is free. https://www.packtpub.com/packt/offers/free-learning
