I have a requirement wherein I need to integrate my web app (built using Progress version 9) with office 365 model. 

That is, a user will login into his/her Office 365 account and then will be able to directly login into the web app without the need of a secondary login. It is somewhat like logging into a web app using your google or facebook account. 

Can anyone shed some light on how this can be achieved using office 365 ?