Often when developing for the web, you may need to spin up a webserver in order to do some testing. If you are on a mac, you may not know that you already have one installed. From any directory, you can simple run the command:
$ python -m SimpleHTTPServer 8080
where 8080 can be any port and http://localhost:8080 will give you a directory listing of that directory and allow you to view any files that are there.