What is Phaser?
Phaser is an HTML5 game framework which aims to help developers make powerful, cross-browser HTML5 games really quickly and, unlike some others, has solely been built to work with the mobile browsers. The only browser requirement is the support of the canvas tag. It also borrows a lot from Flixel.
Download a web server to run the code and see the output.
Windows
We would recommend either WAMP Server or XAMPP and both have easy set-up guides available. Cesanta provide the Mongoose web server. This is a really small application that requires no installation and can run as a single exe file. Instead of an 'all in one' bundle you could also download just a web server on its own. Both Microsoft IIS and Apache can be downloaded for free.
OS X
Install MAMP. This comes in two versions: one free and one paid for.
grunt connect
Grunt is an extremely powerful tool to have installed, regardless if you use it as a web server or not. At its essence it's a JavaScript based task runner and allows you to automate tedious time consuming tasks. We use it in Phaser to build our distribution scripts for example. But it can also be configured with the plugin Connect to serve local files, acting as a web server.
Simple HTTP Server with Python
If you need a quick web server running and you don't want to mess around with setting up Apache or downloading an app, then Python can help. Python comes with a simple built-in HTTP server, which can serve files from any local folder. Naturally the only thing you need to have installed is Python. Read the full guide here
http-server for node.js
http-server is a simple, zero-configuration command-line http server for node.js. It is powerful enough for production usage, but is simple and hackable enough to be used for testing, local development and learning. Or as the web site says "Serving up static files like they were turtles strapped to rockets". Get the npm and instructions from the http-server web site
php 5 built-in web server