Plone is a free and open source content management system built on top of the Zope application server. Plone can be used for any kind of website, including blogs, internet sites, webshops and internal websites. It's also used as a document publishing system and collaboration tool. Plone features a flexible workflow, extensibility and good security.

The Gallery Project (and more recently Gallery Revival) is a web application enabling management and publication of digital photographs and other media. Photo manipulation features includes automatic thumbnails, resizing, rotation, and flipping, among other things. Albums can be organized hierarchically and individually controlled by administrators or privileged users.

Ibexa DXP (formerly eZ platform) is a web content management system that supports the development of customized web applications. It features professional and secure development of web applications, content versioning, media library, role-based rights management, mobile development, sitemaps, search and printing.

Elgg is an award-winning social networking engine, delivering the building blocks that enable businesses, schools, universities and associations to create their own fully-featured social networks and applications. It offers blogging, microblogging, file sharing, networking, groups and a number of other features.