Well I can't give you a source code for that but it isn't that hard.
you just need a desktop app which connects to the login server and send the "request for server list" packet every 5 seconds. you can store the result in a database like MySQL.
so at that moment you got the server stats in the database and now you can build the webpage. you probably need some javascript-ish stuff to refresh the page.
Owh and by the way you could you srproxy or edx33 proxy or drew's simpelest proxy which he released a few days ago in this section.