Quiver - Quiver is a notebook built for programmers.
Xmind - Xmind is a brainstorming and mind mapping application.
GitHub Gist - Gist is a simple way to share snippets and pastes with others.
MindMeister - Create, share and collaboratively work on mind maps with MindMeister, the leading online mind mapping software. Includes apps for iPhone, iPad and Android.
Simple Snippets - Simple Snippets is place to easily create and manage your code snippets. The main features of the Simple Snippets: code highlighting, snippet groups, public and private snippets.
Coggle - Coggle is a simple, beautiful, powerful way of structuring information.