I saw this kicked around on Slashdot, and I don't recall seeing it on this list.  I searched the archives and didn't see anything either.  I'm looking to upgrade our Project Management/Helpdesk services, and also add some Inventory/Asset Management services.  Right now we are using dotproject with the "helpdesk" module.

I like dotproject because of it's project management abilities, but dislike the helpdesk module.  Currently, I'm looking into:

OCS Inventory (for inventory)
http://www.ocsinventory-ng.org/index.php?page=English

GLPI (for helpdesk.  It also will import the OCSI info.)
http://www.glpi-project.org/?lang=en

But is there an all around solution that includes Project Management, Inventory, and Helpdesk that is easy to use and all inclusive?

My requirements are: GPL and Linux.

-Ben