The origin of noncommutativity?

Consistent boundary Poisson structures for open string theory coupled to background B-field are considered using the new approach proposed in hep-th/0111005. It is found that there are infinitely many consistent Poisson structures, each leads to a consistent canonical quantization of open string in the presence of background B-field. Consequently, whether the D-branes to which the open string end points are attached is noncommutative or not depends on the choice of a particular Poisson structure. (C) 2002 Elsevier Science B.V. All rights reserved.