The following features are part of HTML5. This features can be tested in HTML5 compatible browsers. In order to check if your browser supports HTML5 you can run browser check via html5test.com

• Canvas (2D and 3D)
• Channel messaging
• Cross-document messaging
• Geolocation
• MathML
• Microdata
• Server-Sent events
• Scalable Vector Graphics (SVG)
• WebSocket API and protocol
• Web origin concept
• Web storage
• Web SQL database
• Web Workers
• XMLHttpRequest Level 2

There are many smaller in scale features are available in HTML5.