Open source geographic tracking?

Walkingshark writes: I work for a company that needs to track people and equipment across the US as they move to, work on, and leave jobs. The boss has been looking at the typical mix of closed, proprietary software and has also considered building off our existing 10 year old SQL database (with the kind of clunky interface you'd expect from a program built in the late 90's). I'd like to be able to bring him a good open source alternative but so far I haven't been able to find anything that can do what we need. Ultimately, we need to be able to keep track of a few thousand separate pieces of people and equipment, and to move them in dynamically created groups from our locations to and from jobsites in a way that is sharable among between workstations, with updates to location entered at one station being broadcast to all clients in real time. Ideally, this program needs to also give us access to road routing similar to the capability found on Google maps. We'd doubtless need to be able to modify the source for customization, but I was hoping there was something we could find out there that had the core functionality we're looking for.