Gone - An ephemeral to-do list

Workfront - Award winning project management software helps you manage projects in one place. A cloud-based work management tool for marketing and IT teams.

Todoist - Todoist is a to-do list that helps you get organized, at work and in life.

ITM Platform - Cloud-based Project Management Solutions

Check - Check is a unit testing framework for C, which runs on environments such as GNU/Linux, GNU/Hurd, BSD, and Mac OSX. 

Planisware - Planisware PPM software supports NPD and R+D processes to help organizations make confident business decisions.