Outlinely

WorkFlowy is an interesting app that was designed to help you make lists and take notes. It has simple utility that almost anyone can use right away without any training, and it is powerful enough

Moo. do is a comprehensive outliner, task manager, calendar and email client in a single platform. It uses streamlined integration to increase productivity, enhance organization and allow

Dynalist is an outlining software application used to organize and expand upon ideas. It's ideal for any multi-step project or idea, from basic to-do lists to paper organization to step-by-step

The software system, nvALT is a system that allows users to collect and store various notes and files in a way that is easily organized and able to be shared. This system is used by most businesses

Quiver is a notebook tailored to the specific demands of computer programmers.

With Checkvist you can create and share online outlines, project plans, online checklists, and task lists. Very keyboard friendly, with code, Markdown, and OPML support.

OmniOutliner is an amazingly flexible program for creating, collecting, and organizing information for Mac, iPhone, and iPad.

Notational Velocity: modeless, mouseless Mac OS X note-taking application