- Speed improvements.
- HTML Tidy is learning HTML5.
- Syntax highlighting for HTML5 elements, attributes and events.
- Colorizer Styles are easier to create and modify .
- New Edit / Preview / Tidy icons .
- Splash screen that's bigger and cleaner.
- Preview tab remembers document position and supports keyboard scrolling.
- A new option for testing pages in multiple browsers .
In broad strokes, I think you'll see both this software update and HTML-Kit website updates paying more attention to usability and aesthetics, in addition to pure functionality.