There's a new braking system put out by a company named SureStop that controls both front and rear cantilever (side-pull) brake systems with a single brake lever. They seem to be mainly appealing to the safety / children / new bike owner's market.
They say their technology can prevent end-overs as well as skid-outs.
How do they do this? It appears to be more complex than a dual-cable brake lever -- i.e., there seems to be some fore-aft balancing magic that's going on.
Bonus question: If the rear pad loses traction against the wheel (for example: it wears down to its nubbins, slips off the rim, or the rear brake cable breaks), does the user lose all braking - front and rear? Does this then violate the redundant brake regulation in bicycle consumer sales laws?
For example, Japan's JIS 9301:2010 regulations requires "separate braking systems operating on the front and rear wheels respectively" and SureStop says that they are compliant with this standard. Because the front and rear brakes are linked in SureStop, it's unclear to me how they are "separate."