documentr is a Web-based tool for editing and presenting software documentation. It allows you to easily maintain documentation for multiple products and product branches. Edits can easily be copied between branches, with merge conflicts being handled gracefully. It uses Markdown as its markup language, along with some extensions, and has a role-based permission system.
MediaCore is a media-focused CMS. It features rich video and audio support, YouTube/Vimeo integration, HTML5 video, support for the iPad/iPhone, podcasting, iTunes RSS generation, user-submitted content, an embedded media player, and searching. It is highly customizable. There is both a front-end for users and a back-end for administrators. Users can browse videos or podcasts. Users can search for videos by topics and tags. Users can upload videos to the platform; administrators can moderate newly uploaded videos. Administrators can add video, audio, or podcasts. A comment platform for moderation is built-in. Podcasts can be video or audio. It also has automatic iTunes feed generation, automatic RSS feed generation, and feedburner support.
Noostr is a content management system aimed squarely at social news networks. Sites like Reddit, Hacker News, and Digg are all social news aggregators, just like your Noostr site will be. People can sign in, submit news stories or ask questions, and everyone can vote for the best ones. Those top stories float to the front page and generate more traffic, more comments, and more votes.