Yellow is described as 'is for people who make websites. It's a flat-file content management system. Everything is made of files and folders. You can create web pages, blogs, wikis. There's support for Dropbox, Markdown and static content generation' and is an app in the Business & Commerce category. There are more than 25 alternatives to Yellow for a variety of platforms, including Self-Hosted solutions, Online / Web-based, Linux, Windows and Mac. The best alternative is WordPress, which is both free and Open Source. Other great apps like Yellow are Ghost (Free Personal, Open Source), Drupal (Freemium, Open Source), Grav (Free, Open Source) and Joomla (Free, Open Source).
BardCanvas is an Open Source CMS that fits perfectly for blogs/forums/social networks. It is fast (through several cache levels), heavily optimized (it wont collapse the server in high traffic conditions) and constantly improved.
Create a beautiful website with no design or IT skills using the Rocketspark website builder. Enjoyably easy DIY web editing and ecommerce. Great for Designers and Graphic designers, manage your clients with the Rocketspark Studio.