Hours after announcing updates to iBooks and iBooks Author at Tuesday's iPad mini event, Apple has released iBooks 3 through the App Store and iBooks Author 2 through the Mac App Store.

iBooks 3 changes include:

• The ability to see all iBookstore purchases in iCloud in iOS 6
• Endless scrolling
• Receive free updates to purchased books, including new chapters, corrections and other improvements
• Look up definitions in German, Spanish, French, Japanese and Simplified Chinese in iOS6
• Share book excerpts through Facebook, Twitter, Messages or Mail

iBooks Author 2 changes include:

• The ability to create portrait-only books
• Embed custom fonts into books
• Additional interactivity with new scrolling sidebar and pop-over widgets
• Support for mathematical expressions with equation editing using LaTeX and MathML notation
• Automatic media optimization for iPad
• Improved support for embedded audio
• Improved publishing workflow, including automatic book samples and pre-publish checking
• Additional templates
• Version numbering
• Retina display enhancing for the new MacBook Pros
• Other performance and usability improvements