Changelog for DigWP v3.9
@ https://digwp.com/book/errata/

Core Book

- New version in PDF format
- Fine-tuned styles, layout, details
- Updated meta information for PDF versions
- Updated credits and copyright infos
- Updated Intro page with 3.9 info
- Fixed various errata
- Page 28: updated sidebar with more accurate info
- Page 36: updated sidebar with more accurate info
- Created new Demo version of the PDF
- General cleanup, fine-tuning and maintenance

Check out a full list of changes to WP 3.9:

http://wordpress.org/news/2014/04/smith/
http://codex.wordpress.org/Version_3.9