What are some alternatives?
Microsoft Project - Microsoft Office Project gives you robust project management tools with the right blend of...
GanttProject - Project scheduling and management tool
LibrePlan - LibrePlan is an open source web application for project planning, monitoring and control.
Basecamp - A simple and elegant project management system.
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
Smartsheet - Smartsheet is an intuitive online project management tool enabling teams to increase productivity using cloud, collaboration, & mobile technologies.