http://ganttproject.sourceforge.net/
Submitted by Jean-Claude Cutter

Gantt Project is an excellent project management tool, with a surprisingly good depth of features and accessories for a free product. It is distributed under a GNU General Public License, which means you can download it for free.

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However, their site has other option including a java based version of the program, this means you don't even have to download the program to use it. As its name suggest, Gantt Project is excellent for making Gantt charts, and they are excellent for making logical and easy to understand development plans.

Some features I particularly likes was the ability to put in a percentage complete bar, inside that timeline of that particular stage, this makes it easy to see how far along everything is without a lot of hassle. The program, if you use the downloadable version is very simple and easy to use; I was so impressed I now use it for my work. You can add as many tasks as you need, as well as then being able to assign personnel and resources to each task.

In particular the features for the personnel section are the best, you can add team members for a project and assign them to tasks when you set them up, you can also input e-mail addresses as well as phone numbers for each person, and assign them a role in the group. Gantt Project also includes a Milestone feature which is very useful, giving an end goal to aim for with a fixed time, many other project management tools do not support these.

On the technical side, Gantt Project saves files as .xml files, which means they are viewable over the internet as well as transferable to other programs such as Microsoft Project. The installation is very quick and the program is actually very small, being under 10mb. There are very few problems with this tool, my only criticism is that you can't associate files with particular tasks, allowing other team members to get the files they need.

http://ganttproject.sourceforge.net/