What were some of the key goals and motivations for the HTML5 specification?

HTML5 was designed to replace HTML 4, XHTML, and the HTML DOM Level 2. The key goals and motivations behind the HTML5 specification were to:

• Deliver rich content (graphics, movies, etc.) without the need for additional plugins, such as Flash.
• Provide better semantic support for web page structure through new structural element tags.
• Provide a stricter parsing standard to simplify error handling, ensure more consistent cross-browser behaviour, and simplify compatibility with documents written to older standards.
• Provide better cross-platform support whether running on a PC, Tablet, or Smartphone.