What are some alternatives?
When comparing Calligra Plan and Taskjuggler, you can also consider the following products
GanttProject - Project scheduling and management tool
Microsoft Project - Microsoft Office Project gives you robust project management tools with the right blend of...
FoxPlan - Web-based project collaboration tool
GNOME Planner - Planner is the GNOME project management tool licensed under the GPLv2.
Basecamp - A simple and elegant project management system.
Gantter - Community-Powered | Cloud-Based | Project Management & Scheduling