Cascading Style Sheets Level 1 (CCS1) was released in December 1996. Internet Explorer 5.5, Netscape 6, and Opera 5 offer good to excellent support for CSS1. Cascading Style Sheets Level 2 (CSS2) was released in May 1998. At the time of this writing, no browsers fully support CSS2, but some of the new properties are variously supported by the browsers listed above. As always, you must test your work in multiple browsers to ensure the compatibility of your code.