The demo has been packaged as a module for the FOSS GIS Suite (FGS). So, if you already have FGS and PostGIS installed on your machine, all that may be required is:

$ fgs install ivygis-demo:0.0.10 http://www.panix.com/~rst/ivygis

If not, though, or even if you do, you may want to look through these more detailed directions:

If you don't already have FGS, you'll need to install it; the procedure is

$ wget http://www.maptools.org/dl/fgs/self-installers/fgs-mapserver_phpmapscript_4.8.2-1.2-linux-i386.bin
$ chmod +x fgs-mapserver_phpmapscript_4.8.2-1.2-linux-i386.bin
$ ./fgs-mapserver_phpmapscript_4.8.2-1.2-linux-i386.bin

and then answer the questions. Once it's installed, you'll also need to set up the environment variables it needs; you can do that by following the directions it gives you:

$ cd [fgs_install_dir]
$ . setenv.sh

If you don't already have Postgresql or PostGIS installed, you may wish to install them as FGS modules:

$ fgs install postgis-lib:1.0.6 http://dl.maptools.org/dl/fgs/modules/0.2/
$ fgs install postgresql-server:8.0.7 http://dl.maptools.org/dl/fgs/modules/0.2/  
$ fgs start pgsql

If you already have Postgresql and PostGIS installed, this should not be necessary; the ivygis-demo installer just checks to make sure it can find them someplace. You may need to know the location of your site's copy of lwpostgis.sql, though, for the next step.

At this point, all the prerequisites for ivygis-demo should be present on your system; as above, you should just be able to type:

$ fgs install ivygis-demo:0.0.10 http://www.panix.com/~rst/ivygis

This downloads all the required data (including mapserver 4.8.2 and the gmap-demo data, if you don't already have them), and starts a setup script, which in turn loads some of the sample data into the database and runs a few tests. If they pass, you can start the demo server as follows:

$ cd $FGS_HOME/apps/ivygis_demo; script/server

and then access the demos on port 3000 of your machine.