How to change zoom/"green button" behaviour Since Yosemite, the green button in the upper left corner on each window activates the fullscreen mode. By holding alt, it works as before (Mavericks). Is there any possibility (Terminal?) to change this behaviour back to "normal"? For example: holding alt for fullscreen mode?

Update

You can change the behaviour back to "normal" with BetterTouchTool.
Hold down Option key and click the Green button. It will change from the Full Screen button back to a Zoom button.

You can also double-click the empty area in the window frame (title bar) if you don’t have it set to minimize when double-clicking.

However, this soft can help you : https://www.macupdate.com/app/mac/30591/right-zoom

Apple Support