EDM, or Easy Document Manager, is an easy to use and configure document management system. It is designed for small projects invoking up to about 100,000 documents although there are no specific limits in the system.
The user can add documents into the system and classify them with tags instead of using folders. So a document for a budget for 2012, for example, would be tagged with "budget" and "2012" instead of having to decide whether it goes in the budget or 2012 folder.
Documents can be viewed in the web browser if they are a supported type (graphics, Word, Excel, PowerPoint, PDF, text, RTF, and others are supported) and if the suer wants to modify the document she can "check it out" for a certain time. That stops any other user modifying it until it is returned. the system sends reminder emails to the user when it is due back.
The system is fully multi-user and has many privilege options to control what different users can and cannot do. For example, one group of users might be able to view reports and another also modify them.
EDM runs on a Mac server (the initial installation is a cheap Mac Mini) using PHP and MySQL. It uses extensive Applescripts to control document conversion of files which are added. The program doing the conversion is also installed on the server (Microsoft Office, Acrobat Pro, Photoshop, etc).