Alfresco is a document management system that can be implemented in a lot of different use cases. It can be used as the central DMS across the whole company, or dedicated to a specific use in a department. Alfresco is highly configurable and customizable that makes really interesting this solution.
Sometimes, to switch from a paper world to an electronic world can be painful for users. Because of its flexibility, Alfresco is always welcomed by end users. Alfresco becomes really a tool that help the user and not a constraint.
The Alfresco market is bigger and bigger and it's logic. It's really a product that provides innovation quite often. Alfresco implements the standard CMIS 1.1 (before that the standard has been published), they provides interesting tools like IPhone apps or Android apps. The latest 4.2 version provides as well a new re-branded user interface.
Alfresco is split into 2 web applications: the Alfresco core engine, and the Share Collaboration web user interface. If the Share UI is not appropriate to the use case, it's really easy to build an other UI on the top of the engine. Alfresco provides by default a lot of API and you can develop more if needed really simply and quickly.