The performance of distributed systems can be improved when a server
remotely controls off-screen surfaces at a client coupled to the server
via a communications network. The server instructs the client to form an
off-screen surface exhibiting a number of particular attributes. The
client selects and allocates a particular memory region and forms the
off-screen surface therein, as instructed by the server. The server
subsequently provides the client with an indicia of graphical data and
instructs the client to locate the graphical data and to copy the data
into the off-screen surface. In response to an error condition, the
server transmits a duplicate of the off-screen surface to the client with
instructions to update the client's on-screen surface using this
duplicate surface.