Here's the "What's New" page:
http://www.htmlvalidator.com/htmlval/history.html
The improvements & updates include:
- Editor: New option to show all the messages for the line number of the selected message in the Message Window (in the Results Window context/popup menu 'Options->Message Window Shows All Messages')
- Editor: New option to use HTTP/1.0 instead of the default HTTP/1.1 when opening documents from the web (using HTTP/1.0 might resolve some rare authentication issues)
- CSS checker: Added support for CSS3 animations
- HTML checker: Checks for duplicate link and meta tags in the "head" section
- Link checker: Improved MIME type checking for JavaScript and CSS links
- Fixed: Character references in "style" attribute now handled properly
- Fixed: An encoding issue with HTML Tidy Tool that could cause character corruption
- Additions and improvements to TNPL (like new trim functions & more)
- Improved & updated validation message output for both HTML & CSS checkers
- Other miscellaneous tweaks, updates, and improvements
