AirTime is a subtle and simple theme.

FirmaSite is a responsive theme with BuddyPress and bbPress support.

Stark Lite is a minimalist and simple theme.

Memori Jingga is a responsive, clean, and simple theme.

Rockers is a responsive theme with a clean design.

Satu is an elegant single-column responsive theme.

Cazuela is a neutral colored theme.

Ilisa is a clean and minimal theme that can be easily used as a personal portfolio or a business website.

Partition has a light, lively, colorful, yet professional and classic appearance.

Ease is a simple red and white theme.

Nomad is an attractive professional, business or blog theme with an unusual, very narrow orientation and design.

Sensitive is fully responsive theme using Twitter Bootstrap and a Metro-styled accent.

Visual is a dark minimalist theme for displaying photos and images.

Attitude is a simple, clean, and responsive retina-ready theme.

Catch Everest is a simple, clean, and responsive theme.

Liberus is an ideal business related theme that is relatively simple and would suit any blog or website.

Stitch is an elegant, modern theme with optional fixed header.

Chun is a free responsive HTML5 boilerplate theme.

Opus Primus is designed and developed to be extensible and easily modified, based in the principles of decisions not options.

Superhero features full-bleed featured posts and featured images, a fixed header, and subtle CSS3 transitions.

Boiler is a free responsive HTML5 boilerplate theme.

Fluid is a professional, elegant, vibrant, yet fairly simple corporate or business theme that uses varying shades of blue, silver, gray, and white with a semi-abstract water ripple header image that could be easily changed.

Spine is a white, grey, black, and blue two-column theme.

zeeNews is a theme for any news, magazine, or blog.

Pyramid is a simple and clean theme.

Studio is a responsive 1-column theme that includes a static page layout as well as a blog page.

Teal is a responsive magazine theme.

Zen is drenched in white with some paintings in the header and footer.

Earthen is a natural, neutral, earthy, and bright theme.

InfoWay is a clean, simple, and elegant responsive theme.

Photologger is a minimalist theme that is ideal for photo blogs, magazines, and portfolios.

WP StrapSlider Lite is a responsive bootstrap theme.

The goal for Twenty Thirteen is to offer “a focus on blogging, and great support for post formats (which are getting attention on the backend in 3.6 as well).”

If you’d like to see the theme in action, a demo site is available. One thing you’ll notice immediately is that the strong emphasis on whitespace, which has become commonplace in the default themes, is long-gone. Twenty Thirteen is making very bold use of its colors, offering a different color for each post format. The theme also lacks a sidebar by default. It’s designed to focus on blogging after all, so the designers prefer that you leave your widgets to the footer area, but it still does support a sidebar widget area if you really want to put something there.

This theme won’t be for everyone, and really no default theme should. Default themes should showcase the strength of each release’s new features and inspire customization. If you aren’t a fan of Twenty Thirteen, don’t worry, there are still over 1,600 themes to choose from, including Twenty Twelve.

Annotum Sans is a child theme of Annotum with a modern sans-serif style.

Chunk is a straightforward theme with bold typography.

Landscape is a simple responsive theme.

Techy is a simple 2-column, bold, high contrast theme.

Each theme is carefully scrutinized by at least two, if not four, of Automattic’s Theme Team focussing on code quality, usability, and potential theme-specific anomalies. The result is a theme that “just works” out of the box, with no annoying bugs or usability quirks.

Traditionally, things like this have been closely guarded secrets, but Automattic has publicly released their theme guidelines so anyone can benefit from them. These guidelines, are not a requirement if you want to just develop a theme for WordPress in general, but they are still some great coding practices worth following if you want your theme to “just work” too.

BT Extended is a newspaper style with a responsive four column fluid layout.

Cocoa is a basic, simple, minimalist theme of browns and black with just a touch of cinnamon red thrown in for flavor.

Columbus is a real estate theme with a two-column layout and top-level page navigation.

Photogram is designed to integrate your WordPress site with Instagram and Pinterest in a few simple clicks.

Simplify is a responsive theme designed for small businesses.

Bubbly is an attractive theme with green and touches of white on a subtle background of light bubbles.

Forever makes it easy to wrap your wedding up in a neat little blog.

Quintus has an old-style appeal with semi-academic graciousness and elegant typography.

Reddle features a minimal design which elegantly adapts to how you want to use your blog and what you want to use it for.

Vertigo is a stylish and fun theme with one column, a custom header, and a custom accent color.

Paradise is an all-purpose clean and minimalistic theme.

Placard is a bold, bright, and colorful professional or business theme that is somewhat inspired by the Windows 8 desktop.

Sukelius Magazine is a magazine theme with theme options and a content slider.