Keyword Parameters

You do have the option of using a GUI native drawing backend, eg GTK
instead of GTKAgg or WX instead of WXAgg. Because we use double
buffering in GTK, it may not help (Steve -- would it be possible to
make double buffering optional?) The native GTK drawing is inferior
to Agg, in my view, but you may be willing to trade quality for
speed.

I've added a 'DBL_BUFFER' variable to backend_gtk.py to switch on/off
double buffering for the GTK backend.
Switching off double buffering makes widget redraws flicker (as you'd
expect). I can't see how disabling double buffering has any value, or
how it could be useful when running python remotely, perhaps I'm wrong -
feel free to test it and let me know if it does have a use.

Steve