Kindle Format 8

File extension: .azw,.azw3,.azw4 Developed by: Type of format: Ebook file format MIME: application/vnd.-amazon.-mobi8-ebook
Kindle devices are designed to use Amazon's own e-book formats: AZW. In late 2011, the Kindle Fire introduced "Kindle Format 8" (KF8), also known as AZW3 file format. AZW3 supports a subset of HTML5 and CSS3 features, while acting as a container for a backwards-compatible MOBI content document.