The New WordPress.com - Publishing platform, reinvented, open source w/ new Mac app
Lavalite - PHP CMS built with Laravel and Bootstrap.
Blogboard - Engineering blogs from top tech companies
DEV.to - Where software engineers connect, build their resumes, and grow.
Typehut - Super simple publishing platform
ApostropheCMS - Apostrophe is a powerful website builder platform built on an enterprise open source CMS, offering in-context live editing, visual design tools, and multisite enablement in a full stack JS environment.