HTML 4.0
1997 December 18th
W3C published official recommendations for the HTML 4.0 specification. The HTML 4.0 specification was divided into three variants: Strict, Transitional, and Frameset, and its aim was to separate the HTML semantics and the document layout (formatted using only CSS) into two separate parts. In December 1999, recommendations were published for a revised version, HTML 4.01.