Is there an open 'project' file format alternative to Microsoft's *.mpp?

Question

There's the open document format (ODF) for word processors, but is there an open standardised format for project files? I'm currently using Gnome Planner which I downloaded from the Software Centre, but my course teaches us to use OpenProj, which I don't really like since it's pretty sluggish on my computer. I'm attempting to import the *.planner file from Planner into OpenProj, but it's not working. Planner exports to three different file format: *.planner, *.mrproject and *.html and none of them can be imported to OpenProj, whose default filetype is *.pod and can also export to *.xml and *.pdf. This all seems a bit messy to me.

Answer 1

A visit to http://www.osalt.com yielded a link to GanttProject. Among the features listed on their website is the ability to "import projects from and export them to Microsoft Project formats [and] export to spreadsheets with CSV."

I have no experience with this type of software but osalt.com would always be my first stop for a question like this.

Answer 2

http://sourceforge.net/projects/openproj/

OpenProj is an open-source desktop project management application similar to Microsoft Project. OpenProj has a familiar user interface and even opens existing MS Project files. OpenProj is interoperable with Project, Gantt Charts and PERT charts.

Answer 3

ProjectLibre is an actively maintained fork of openproj that is able to open .planner files.