Javascript is a scripting language used to make both client side (browser) and server side (node.js) applications. As of the introduction of HTML5, it is getting increasingly more popular as a choice for game development, usually utilizing the <canvas> tag.

Characteristics:

• object oriented
• prototype based
• C-style syntax

Typing:

• dynamic
• weak
• duck

Game programming in Javascript:

http://gamedev.stackexchange.com/questions/23076/good-resources-for-javascript-2d-game-programming