There is a plethora of languages to write documentation and documents. From extremely powerful and complex such as L A T E X to extremely simple such as Markdown. In this technical article we present Pillar a versatile and ex-tensible lightweight markup language. Pillar's document model and open architecture support exporting from Pillar to various formats such as ASCIIDoc, HTML, L A T E X and Markdown. Pillar is currently used to write books, documentation, websites and slide decks (through Beamer and DeckJS). Pillar specially shines when advanced features are needed such as multiple exports (e.g., a printed book and web pages), internal references (e.g., links to figures with captions) and content generation (e.g., to give an up-to-date code size of a documented software).