This package has HTML Tidy for checking HTML documents for errors, including HTML5 documents, and improved preview window. NextBackEdit with full-control. Code helpers, generators and shortcuts including Zen Coding are there when you need them. Out-of-the-box version control and backups give you quick access to revisions without having to configure servers.
Preview in the editor (full-screen or split-screen live previews), in another window, on multiple monitors, in multiple browsers and even through external devices (multi-device live preview on smartphones/tablets including iOS, Android, Windows Phone and Blackberry).
Save time and catch errors quickly by previewing as you edit HTML5, Markdown, LESS and other file types. Built-in HTML Tidy can point out invalid markup and suggest improvements. Or use industry-standard W3C HTML/CSS Validators with a single click.
In addition to optional plugins, some of the many powerful tools included are displaying color below each HTML/CSS hex/rgb() color, highlighting of matching block, instant viewing of matches as you select, and searches within tags / attributes / classes / styles.
Keep multiple projects open at the same time (with color labels in tabs), create virtual folders to logically organize files from multiple sources and access local/network/FTP folders. Or skip all of it and simply open files from local folders.