HTML Versions

First, a quick rundown of all the HTML versions since HTML was invented.

HTML 1.0: This was the barebones version of HTML and the very first release of the language.
HTML 2.0: This version was introduced in 1995 and it gradually evolved to allow extra capabilities including: form-based file upload, tables, client-side image maps and internationalization.
HTML 3.2: In an attempt to ensure development of standards for the World Wide Web, the World Wide Web Consortium (W3C) was founded by Tim Berners-Lee in 1994. By 1997, they published HTML 3.2.
HTML 4.0: Later in 1997, the W3C released HTML 4.0 — a version that adopted many browser-specific element types and attributes.
HTML 4.0 will later be reissued with minor edits in 1998.
HTML 4.01: In December 1999, HTML 4.01 was released.
XHTML: The specifications for this was introduced in 2000 and it was recommended to be used as the joint-standard with HTML 4.01. It incorporated XML to ensure code is properly written and to ensure interoperability between programming languages.
HTML5: The W3C published HTML5 as a recommendation in October 2014 and will later release HTML 5.1 in November 2016.