What is a good tool to keep track of IT inventory? Systems that are installed and running, parts being ordered, that sort of thing. I'd love a central, web based system (preferably something we can customize) but my searching so far has resulted in a lot of dead open source projects that havn't been updated in a few years and poorly created commercial websites that don't do a very good job describing their product.

The software doesn't have to be free or open source - a good commercial alternative is fine. It doesn't even need to be a web-based tool, that's just what I thought would be simplist to find and easiest to deploy. The number of assets that it will be tracking will be in the dozens, so it doesn't have to be a super high-end enterprise solution but it does need to do a better job than an excel sheet in a shared folder (which is our current "solution")