[haiku] New feature

Hi people,

some weeks ago I've installed a recent nightly after being idle about
Haiku (actually with everything related to computing) in the past
months, and I've discovered a new feature; while holding the CTRL +
ALT keys and passing the mouse over the borders of a window those
change their color to a conspicous blue, but I haven't still got
what's meant for!!!

Please, can I have some hint?

Best regards to everyone,
Michele aka zuMi

Other related posts: