Quantization of a relativistic string

Different approaches to the quantization of a relativistic string are compared critically. It is shown that Rohrlich's noncanonical algebras can be obtained in the framework of the method of quantization of systems with constraints developed by Dirac. A special transformation of the variables makes it possible to construct an operator realization of these algebras and show that the method of quantization using noncanonieal algebras is equivalent to the method of covariant quantization.