Before you run your application, you need to start a web server to serve the TVML and JavaScript files. To do this:

1. Open Terminal
2. Navigate to the 'Servers' folder 
3. Here, you can choose one of the two servers: HelloWorld or TEDTalks – use `cd HelloWorld` or `cd TEDTalks` to navigate to the folder
4. Start a web server by using `python -m SimpleHTTPServer 9001' where 9001 is the port number
5. Accept any incoming connections

You're done! The server should serve up the necessary files now. 