Bike is a Web application framework that can make feature-rich applications using HTML files only. You need no database setup (by default), no scheme definition, and no command-line voodoo. Just put a good old HTML file under skin/, and your new app is already running. Bike is front-ended by Rack, back-ended by Sequel.
AldoContent is a lightweight CMS focused on usability and simplicity. It is designed for multilingual Web sites and can have sections with public and private content. It has file management, is extensible with plugins, and uses gettext for localization. Is written in PHP for a MySQL backend.
papaya CMS is a Web Content Management System based on open standards (including XML, XSLT, PHP, and MySQL/PostgreSQL). It is compatible with almost every operating system, is platform-independent, is multi-lingual, offers great usability, and is easy to extend via its plugin system. It is scalable and perfect for business websites.
AlphaLemon CMS is a content management system built on top of the Symfony2 framework. It is designed to make it as easy as possibile to manage a Web site without requiring programming or a large learning curve, while giving developers a robust and flexible framework on which to build Web applications and distributable extensions.
Molinos CMS is a modular CMS. It supports multiple Web sites per installation, multiple domains per Web site, and different subdomains for different Web site sections. It uses XSLT for templating; templates can be organized in themes, which can be applied to either all pages or particular pages. It can use MySQL or SQLite for data stoarge; all data is available in XML format, ready to use by templates and scripts. User groups (roles) and advanced ACL can be used to control access to that data. It supports many caching and code optimization techniques. Data storage is optimized to minimize queries required to display pages. There are modules for integrating with various third-party services (over 70 modules). Modules are simple to write using the provided documentation (currently only available in Russian). Web sites can use local and system modules simultaneously. It works with most Web servers, and has a built-in Web server (for localhost development). It also has a CLI for most tasks.
PinaCMS is a batch Web site launcher. Use it as a content management system for a Web site chain or build your own SaaS CMS solution. It allows you to easily create, manage, and replicate common components, control each site individually or apply updates to all of them simultaneously, offer your clients a quick and easy way to create and manage their Web sites, and enjoy easy administration and a flexible mechanism for access control.
Chyrp is a blogging engine designed to be very lightweight while retaining functionality. It has powerful theme and extension engines, so you can personalize it however you want. The code is well-documented, and it has a very strong structure that's loosely based on the MVC design pattern. Chyrp allows importation from several different blogging engines and uses a system called "feathers", which are basically templates for custom posts.
Simblog aims to be one of the most easy-to-use and lightweight blogging platforms. It emphasizes user experience, workflow, and ease of use without neglecting usability and extensibility. It will take full advantage of what HTML5 and CSS3 have to offer without delving too deeply into experimental features. It is built on its own lightweight framework, which allows a high degree of extensibility and modularity for your blog. It uses Smarty as a templating engine (which also provides a caching mechanism), jQuery and Kendo UI for frontend design, and MySQL as a database.