barrier - 2.4.0+dfsg-3 main

Barrier lets you easily share a single mouse and keyboard between
multiple computers with different operating systems, each with its
own display, without special hardware. It's intended for users
with multiple computers on their desk since each system uses its
own display.
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Redirecting the mouse and keyboard is as simple as moving the mouse
off the edge of your screen. Barrier also merges the clipboards of
all the systems into one, allowing cut-and-paste between systems.
Furthermore, it synchronizes screen savers so they all start and stop
together and, if screen locking is enabled, only one screen requires
a password to unlock them all.