Mapserv CGI, PHP-MapScript and Python MapScript are included. PHP-MapScript is for PHP CGI-only for now. Of course, PHP-MapScript needs PHP, but the CGI mapserv will run without PHP. Python MapScript requires the Python 2.5 package on Tiger (Python 2.5 is included in Leopard). MapServer requires the UnixImageIO, FreeType, GEOS 3, PROJ and GDAL frameworks. PDF support is currently in limbo, and will hopefully return soon.
For testing MapServer, look at the demos and tutorials on the MapServer website.
Included also are simple (and a bit old) drag-n-drop GUIs for the shptree, tile4ms and sortshp tools. The other tools you will have to use from the terminal.
I didn't catch a bug in Apple's beta PackageMaker soon enough, and MapServer 5.0.3-1 will install everything directly in your HD root. You only need to do this if you installed 5.0.3-1. There are two steps to clean this up:
1: Trash the files. Most of them are obvious, as they have 'mapserv' or 'mapscript' in their name. The framework files are probably loose, these are:
2: Repair Permissions. The installer may have left the root with the wrong permissions. Run Disk Utility, and select your boot HD. From the First Aid tab, click the Repair Disk Permissions button.
Sorry for the mess.
For an up-to-date MapServer that runs on Panther, see the build instructions to compile from source.