A co-worker of mine used to keep all his notes in one large notepad file. He literally used Windows notepad. Then when he needed to check his notes, he would simply do keyword searches on the file. It went back years and proved to be a better reference than a fancy knowledge base. This file is a similar dump for myself. It includes everything I read, notes and cheatsheets. Organized with markdown but may move for emacs org mode format in the future. Creative commons license.