There are many alternatives to GanttProject for Linux if you are looking for a replacement. The best Linux alternative is ProjectLibre, which is both free and Open Source. If that doesn't suit you, our users have ranked more than 100 alternatives to GanttProject and many of them are available for Linux so hopefully you can find a suitable replacement. Other interesting Linux alternatives to GanttProject are Bitrix24 (Freemium), Planner (Free, Open Source), LibrePlan (Freemium, Open Source) and ActiveCollab (Freemium).
Task manager with Todoist support. How Planner works: 1. Collect your Ideas - The Inbox is your default task list in Planner. When you add a task, it goes straight to your Inbox unless you specify that the task goes into a project.
ProjeQtOr (formely Project'Or RIA) is an open source Project Management Software, gathering in a single tool every functionality needed to organize your projects. The objective is to keep it simple, easy to use on a day to day activity.
TaskFalcon is a free project planning and tracking software, which keeps track of your tasks, resources, dependencies and supports features like resource collaboration, partial utilisation. It is free to use and can output GANTT- and resource charts in no time.