Today I added an installer
create a folder in /usr/www/ ex: /usr/www/wizard.
give read and write right to www-data on this folder.
copy index.php into this folder.
then go to http://localhost/wizard with your brower and follow the instruction.
The installer can install as much instance as you want.
PS. All dev and testing are made on linux Ubuntu 14.04.1 LTS with standard lamp server and no fancy configuration.