Forms vs OAF

I wonder in which cases Forms should be used in which cases OAF should be used? After a research i see that forms work on a client and OAF (Oracle Application Framework) is claimed to have less coding effort (mostly because of reusable codes), low cost. On the other hand there is a R11 - R12 reusability subject of these developments; Jdeveloper (OAF) for R11 is not supporting R12 and Jdeveloper (OAF) for R12 is not supporting R11 either. Though Forms Builder6 for R11 is not supporting R12 but Forms Builder10 for R12 supports R11.
One more face of the subject is user friendliness; OAF pages does not require anything but a browser though Forms requires specific Java version installed. Therefore if too many users will use the screen or users will access to the screen from uncontrollable computers then using OAF seems to be a better solution.

Indeed i learnt that new question is OAF versus ADF (Oracle Application Development Framework). ADF is a part of next generation Fusion Middleware but Fusion Applications is still in darkness. ADF can be used for EBS also but not officially supported and does not carry the advantages of OAF for R11 and R12. As a result OAF is suggested for new developments for being html based and being expected to be easily transformable to use in Fusion Applications.