Jamroom is a content management system (CMS) for building community sites. People sign up on your site and get a profile. On that profile they add content, such as blog posts, audio, video, photos and events, and other members follow them, comment and share. You decide which features each kind of profile gets, and how the whole site looks.
Jamroom is written in PHP and stores its data in a MySQL (or MariaDB) database. It runs on a Linux web server: either one you rent or run yourself, or a Jamroom Hosted server.
Everything in Jamroom is a module or a skin:
You add modules and skins from the Marketplace, which is inside your site's Admin Control Panel (ACP). Some are free and some are premium (paid). Installing or updating one is a click: you don't upload files yourself.
The Jamroom core is open source under the Mozilla Public License 2.0. The Jamroom Open Source download (version 7.0.3 at the time of writing) has 29 modules and one skin, Elastic 2. Among the modules:
It's a complete working site. You add more from the Marketplace as you need it.