CodeBase.es

php

• PHP Mail tester [demo|download]
  Checks if an email account is valid (gets MX records and asks to mail servers).
  

javascript/html5

• JSGB 0.02 a JavaScript GameBoy Emulator [demo|download]
  It's a Nintendo GameBoy Emulator and debugger (written in JavaScript).
  It runs many games at full speed (using a browser with a fast JavaScript engine).
  Recommended browser: Chromium 4+.
• Snow effect [demo|source]
  Creates an animated snow falling effect using a canvas object.
  
• HTML5 Web Storage / localStorage sample [demo|source]
  A simple example on how to use HTML5's Web Storage to save data without using cookies, gears, flash or server side code. The browser stores the data as a list of list of key/value pairs. Very easy.
  Tested in Firefox 3.