Treehugger used to do a "Stair of the Week" feature, promoting stairs as a healthy, low energy way of moving between floors. Often they would be gorgeous cantilevered stairs that cost a fortune to build. Now Diamond Stairs has designed a prefab cantilevered stair that lets anyone break the building codes by building a stair without a guard or handrail. (They do have an option for a glass guard, but it just isn't the same thing)
Each step assembly comes with a tread, two brackets, bolts and a telescoping support stud. The stud is installed with the brackets protruding outward. A wall is then installed around the brackets. Once the wall is finished the treads may be bolted in place.
They showed it at ICFF with a guard, and it is just not the same thing;
People should be allowed to do this within the privacy of their own homes. And with this system, they now can, out of the box. More at Diamond Stairs