A few people ask about WordPress Themes that are already working with the Full-Site Editing system and the new Site Editor. Here is a List as of July 2021.
The Themes are all built while Full-Site Editing is under active development and many features are experimental. Do not use in production or live site. Expect the themes to be wonky at times, until developers have a chance to update the themes for new Gutenberg plugin version. In short: There will be Dragons! 🐉
Oh, yes. You also need to install the Gutenberg plugin.
For the lastest updates pre-release, use the Gutenberg Nightly
Themes for Full-Site Editing in the WordPress repository
I only used TT1 Blocks Theme for FSE-Testing. I rely mostly on Justin Tadlock or others to provide more insights on the various themes. The articles are linked with the theme header.
Armando by Carolyn Newmark
Block Base by Automattic
Using Blockbase for a theme experiment (ThemeShaper) by Kjell Reigstad
The Automattic Theme Team Announces Blockbase, Its New Block Parent Theme (WordPress Tavern) by Justin Tadlock
Blockbase: A parent theme for block themes (ThemeShaper) by Ben Dwyer
Child themes of Block Base
Mayland Blocks by Automattic
Seedlet Blocks by Automattic
Block-Based Bosco by Fränk Klein
Clove by Anariel Design
Hansen by Uxl Themes
Naledi by Anariel Design
Anariel Design Launches Naledi, a Block-Based WordPress Theme (WordPress Tavern)
Q by Ari Stathopoulos
Rick by WPEntire
TT1 Blocks by WordPress contributors
This is the FSE sibling of the Twenty-Twenty-One Theme
If you find any theme missing in this list, let me know.
WordPress Theme team resources
The themes team share their experisments on Github. Some of the listed themes made it as stand alone theme into the repository listed above.
Contributors also included a script to generate a theme with the minimum necessary to build your own block theme:
Every other week, the themes team meets discussion Block-based themes: 2nd and 4th Tuesday at 15:00 UTC (11am EDT) wp-slack channel #themereview
Every week, the Themes team published a roundup post about newly merged changes, and what is discussed on the GitHub repo for Gutenberg. The post also has a few overview issues so you can always catch up on what is in the works. Follow the #gutenberg-themes-roundup tag on the make-blog/themes
Anne McCarthy, developer relations and program manage for the FSE outreach published a post on ThemeShaper with more Resources for block theme development