How to grab the screen on mac?
I have tried jit.desktop, unfortunately it seems doesn't work on my mac. Is there any other object that can grab screens as video input in real time?

check out camtwist:
http://camtwiststudio.com/2011/06/12/desktop-vs-desktop/
Thanks, how to make it connect to Max?
you'll use syphon--see attached screenshot.

Syphoner works great too :
http://www.sigmasix.ch/syphoner/
Thank you guys!
I've tried the screenshot you upload, but in my max, the [jit.gl.syphonclient] is red... I have download this patch on github, something I missed?
@ALAIN
I download this app, it's work, but how can I use it in Max?
You have to download the syphon externals from the Package Manager. Also check how I do it with Syphoner or ScreenCaptureSyphon. https://youtu.be/31zZ2AC9bOo
thanks, my Max is v7.0.0, how can I download the syphon?
...or fix that jit.desktop issue.
it's seems jit.desktop not fit 64-bit, syphon not work in max7.0??
@2K thanks