Is "t@b ZS4 Video Editor" linear or non-linear...?

I read all through Issues Of Linearity and I still don't understand the one thing that matters most - is "t@b ZS4 Video Editor" linear (like Virtualdub) or non-linear...?

Thanks!

 

non-linear video

not much audio features. I'd say the video end of zs4 is significantly non-linear, i think.