A mongo based minecraft server tracker
I use this to show player counts of popular servers as well as user-submitted servers at status.mc-api.net
You will need a working MongoDB installation. You will also need to have basic knowledge with both Mongo and PHP.
To setup you will need to edit the status.api.php file and input your mongo connection details.
You will need to create a collection called tracker_servers and add the servers you want to track (see this file for an example list).
You will also need a cron job running at your chosen interval to ping the servers and update the database.