TiddlyWiki - a non-linear personal web notebook
Evernote - Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.
Personaldb - Note taking with non-linear power
Walling - Walling is your visual space to capture ideas and organize projects.
Roam Research - A note-taking tool for networked thought
Sublime Text - Sublime Text is a sophisticated text editor for code, html and prose - any kind of text file. You'll love the slick user interface and extraordinary features. Fully customizable with macros, and syntax highlighting for most major languages.