HTML has come a long way since its inception in 1990s and the new HTNL avatar is HTML5, an open standard. Steve Jobs prefers it over Adobe Flash for instance. Lots of development is going to happen in HTML5 in the coming days and some framework for developers are listed below.
HTML5/CSS3 are fairly new but few frameworks for developers are already released. 52framework for instance, one the first frameworks to be released has lot of useful features. It supports all htnl5 tags, script embed, Modified Reset Stylesheet for HTML5 and CSS3. There are more features than you would expect and more details here – 52framework
LessFramework is a CSS grid system for designing adaptive websites. It contains 4 layouts and 3 sets of typography presets, all based on a single grid.
Built with typographic standards in mind, Baseline makes it easy to develop a website with a pleasing grid and good typography. Baseline starts with several files to reset the browser’s default behavior, build a basic typographic layout — including style for HTML forms and new HTML 5 elements — and build a simple grid system.
Build blazingly fast, desktop-class web applications. SproutCore is an HTML5 application framework for building responsive, desktop-caliber apps in any modern web browser, without plugins.
OpenLaszlo (Open Source)
OpenLaszlo – The run-anywhere rich internet platform that supports rapid app development. Has LZX declarative language, supports active animation and flexible layouts.
Jo HTML5 (for Mobile App and Open Source)
JoApp is a cross platform and open source mobile widget framework.
A HTML5 Mobile Web App Framework. Sencha Touch allows you to develop mobile web apps that look and feel native on iPhone and Android touch devices.
LimeJS is a HTML5 game framework for building fast, native-experience games for all modern touchscreens and desktop browsers.
Baker EBOOK Framework
Baker is a open source HTML5 ebook framework for publishing ebooks for iPad.