Launched by Adobe in 2012, Brackets is an open-source code editor for web developers.
At first glance, the program looks rather basic. A left-hand bar lists your current working files (HTML, images, CSS), an unnecessary sidebar contains only two lonely-looking icons, there's a menu bar, the document you're editing, and that's about it. Start work, though, and extra features quickly appear.
As your code gets more lengthy, so Brackets helps to ease navigation. Click in an HTML tag name, a class or ID attribute, choose the Quick Edit option, and any relevant rules appear in an inline editor. You get to see and tweak CSS code as required, without having to manually switch between files.
Click the Live Preview button on the sidebar and life gets even easier. Chrome pops up (as long as you've installed it, of course) to render the current page, and this preview display is then updated in real time, as you edit your HTML and CSS. It's all very smooth, no messy screen refreshes required, and great for providing immediate feedback on your ideas.
There are plenty of other worthwhile features. Hover your mouse over an image, colour or gradient, and a preview appears; WebPlatform.org-sourced documentation is available on CSS properties and values, as required; there are "Find", "Find in files" and "Replace" tools, all with regular expression support.