FireBug Extension and jQuery
Javascript is becoming more and more important in today's web sites. With all the hype around web 2.0 (whatever that means), AJAX and Rich User Interfaces, developers will need better tools to work with Javascript. Here are two recent tools that I found to be extremely helpful:
jQuery is a Javascript library that takes this motto to heart: Writing Javascript code should be fun. jQuery acheives this goal by taking common, repetitive, tasks, stripping out all the unnecessary markup, and leaving them short, smart and understandable.
An example:
$("p.surprise").addClass("ohmy").show("slow");
The above code snippet looks for all paragraphs that have a class of 'surprise', adds the class 'ohmy' to them, then slowly reveals them.
FireBug is a new tool for Firefox that aids with debugging Javascript, DHTML, and Ajax. It is like a combination of the Javascript Console, DOM Inspector, and a command line Javascript interpreter.