Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Eventbrite - Discover Great Events or Create Your Own & Sell Tickets
Remember The Milk - Remember The Milk is a task and time management application for mobile devices.
Splash - Anyone can create a Splash event, whether you're a company hosting a single event or an individual hosting a personal event like a birthday or wedding. Get Started for Free. Text goes here. X. Full Event Program.
Org mode - Org: an Emacs Mode for Notes, Planning, and Authoring
Eventzilla - Eventzilla lets you sell tickets online and manage attendees from one integrated application.