This is an integration of the great CSS3-PIE for migrating most useful CSS3-Features to cross-platform and IE.
The CSS3-PIE ports some most useful CSS3-Features to the IE-Platform (IE6) using some Javascript and IE-VML.

For a introduction-demo on TYPO3 just include this in Typoscript:
Typoscript-Setup
page.includeCSS.css3PIE_demo  EXT:tnm_css3pie/res/example.css
page.50  TEXT
page.50.value  div class"css3pie_demo"CSS3 Pie Works ;-)/div
/Typoscript-Setup

For a complete reference of features and more informations, please visit the CSS3PIE Webpage:
http://css3pie.com

Documentation:
http://css3pie.com/documentation/supported-css3-features/