Wordpress, creating a different website on a subdirectory

I got a wordpress website on the main domain and in a subdirectory I want got another third-party web application I would like to run.

Eg. www.example.com <-- stores the main Wordpress website http://ift.tt/1sHWriz <-- runs a third party web application.

Is this possible or should I host the web application in a subdomain instead?

via Chebli Mohamed