One of the main barriers I had to using MapServer as a web GIS server was that layers had to be symbolised i
n a text editor, using a MAPFILE. It was cumbersome to keep editing and refreshing a browser, there was no easy way to check for errors, and you have to learn the syntax and keywords.
Whilst this is ok for smaller projects where I could make these myself, larger projects require non-programmers to gather data, symbolise it, and handle the map layouts and creation.
I’ve just discovered that another of the OSGeo‘s projects, Quantum GIS (often abbreviated to QGIS) has a tool that can take a map project created and symbolised in the desktop application, and export it to a MAPFILE which can be read by MapServer. This seems to be the missing link in a complete Open Source GIS stack.