This Recommendation defines a protocol that supports multipoint application sharing. The T.128 protocol supports multipoint computer application sharing by allowing a view onto a computer application executing at one site to be advertised within a session to other sites. Each site can, under specified conditions, take control of the shared computer application by sending remote keyboard and pointing device information. This style of application sharing does not require and does not make provision for synchronizing multiple instances of the same computer application running at multiple sites. Instead, it enables remote viewing and control of a single application instance to provide the illusion that the application is running locally. This Recommendation uses services provided by Recommendations T.122 (MCS) and T.124 (GCC). This revised version of T.128 introduces a number of clarifications to the previous version.