gtk-vnc is a VNC viewer widget for GTK. It is built using
coroutines allowing it to be completely asynchronous while
remaining single threaded. It provides a core C library, and
bindings for Python (PyGTK)

This script builds both the gtk+2 and gtk+3 versions of the
library: to avoid building the gtk+3 version, pass "GTK3=no"
launching the SlackBuild, like this
  GTK3=no ./gtk-vnc.SlackBuild