This is a live bus tracking system using the API provided by Washington Metropolitan Area Transit Authority (WMATA). The original data are in JSON format and we converted them into GEOJSON so that we could display them on the map using Leaflet. To use this application, type in the bus route you want to check and the refreshing time interval (in seconds), then click on the "Find Bus!" button. Buses of the specified route will then be displayed on the map as blue markers whose positions are updated at the time interval you entered. Clicking on a blue marker will pop up a window which contains detailed information of the bus, including its route number, general direction, destination and deviation from schedule. Panels on the left show some of the available routes in the Metropolitan D.C. area, which is divided into three regions (D.C., Maryland, and Virginia). Links to their specific roadmap as well as the full list of bus routes can be accessed via clicking on the routes respectively.