Many of the newer designs are "responsive" themes, which means the theme is designed to work with virtually any display size from hi-res monitors to smartphones.
Resources: Free WordPress themes 2013
- 40+ Best Free WordPress Themes Collection for September 2013 – TechVerse
- The Themes of Summer 2013: 18 Fresh Free WordPress Themes – Noupe
- 10 Best Free WordPress Themes Of 2013 – Forbes
- 21 Free Responsive WordPress Themes – Designer Ledger
- 20 Awesome Free Responsive WordPress Themes 2013 Edition
- List of 36 Best Free Premium WordPress(WP) Themes for 2013 – WhatsWithTech
- 225+ Free Responsive WordPress Themes – Design Razzi Web Design Magazine
- 25+ Best Free WordPress Themes of 2013 – Magazine Hive
- Top 5 Free WordPress Themes of the Month — August 2013 Edition
- Top 5 Free WordPress Themes of the Month — July 2013 Edition
Demos: A few notable free WordPress themes
These links are demos of some of the WordPress themes I found interesting. It is the list above which showcases many dozens or even hundreds of nice, free, newish WordPress themes.