The FTP site containing downloads to the Wonderware installers is a little difficult to find, but it is publicly available. You can download the full InTouch HMI, Industrial Application Server, and other related packages here:

ftp://ftp.west.wonderware.com/Wonderware/

Alternatively, you can download files from their PACWest website, although these downloads require a login and password. Either way, you can then activate the software using your license code, which is obtained from your Wonderware supplier.