Why a re-introduction? Because JavaScript has a reasonable claim to being the world's most misunderstood programming language. While often derided as a toy, beneath its deceptive simplicity lie some powerful language features. The last year has seen the launch of a number of high profile JavaScript applications, showing that deeper knowledge of this technology is an important skill for any web developer.

It's useful to start with an idea of the language's history. JavaScript was created in 1995 by Brendan Eich, an engineer at Netscape, and first released with Netscape 2 early in 1996. It's was originally going to be called LiveScript, but was renamed in an ill-fated marketing decision to capitalise on the popularity of Sun Microsystem's Java language - despite the two having very little in common. This has been a source of confusion ever since.