GanttProject is an open source, free, popular and multiplatform graphical application implemented in Java and designed from the offset to be used for managing and scheduling projects using Gantt charts. The software is an alternative to the Microsoft Project application.

With this application you will be able to break down a project into tasks, draw dependencies constraints between multiple tasks, define milestones, as well as to manage various resources. Tasks may have cost, priority, fill pattern, color, text notes, and user-defined custom fields.

It also allows you to assign human resources to work on tasks, to generate PERT charts straight from the Gantt chart for read-only view, to save charts as PNG images, to generate HTML and PDF reports, and to use other types of constraints or add lags.

Another interesting feature is the ability to use a work breakdown structure for organizing tasks. A hierarchical tree can be used to show costs, progress and dates of lower level tasks. You can hide unimportant tasks by collapsing summary tasks, or to compare the state of the current project with previous plans by creating baselines.

Taking a look under the hood of the GanttProject software, we can notice that it has been written entirely in the Java programming language and that it uses the Java Swing technology for its graphical user interface (GUI). The software is translated into more than 20 languages.

Being written in Java means that the project is platform-independent, supported on any OSes where the Java Runtime Environment (JRE) is available, including all GNU/Linux distributions, as well as the Microsoft Windows and Mac OS X operating systems. It has been successfully tested on 32-bit and 64-bit computers.