When you're putting together a complicated presentation, you use a tool like PowerPoint. Need to present complex financial data? Excel is probably your go-to tool. But what about building a website? Since the underlying code is just plain old unformatted text, often the weapon of choice is just a text editor like Notepad or TextEdit. If that seems like a lot of pressure to put on a tool like that, maybe you could check out Aptana Studio.
Aptana Studio is a free download. It's available for Linux, Mac, and Windows systems.