Boxcutter in Blender 2.8 was re-written from the ground up.
Every feature has been re-analyzed and assembled with new workflows in mind.
Starting Boxcutter is as easy as pressing Alt plus W or clicking the icon in the T panel.
Box, Circle and NGON are available to select from however we have more to add.
Click and drag on the surface to begin a surface draw.
With depth the response is instant.
In addition to cut there is make, slice, join, and knife.
You are able to modify your shapes using bevel, array, and solidify.
Surface alignment is the default when drawing with your cursor on the object.
View is activated automatically by initializing drawing off of the surface.
Alternatively there is a grid system for getting the perfect orientation.
The behavior panel is also loaded with options intended on making your experience personal and specific to your needs.
When Boxcutter is active, pressing D will bring up the redesigned D pie which can be useful for adjusting parameters on the fly.
Selecting any other active tool ends boxcutter making exit.
There is much more to Boxcutter as you dive in but this serves as a cursory overview.