Special Issue on Deformation Quantization

The need for quantization was felt already around 1900, but quantum mechanics proper started about 80 years ago. It then took half a century to express in a mathematically and physically precise way what was intuitively felt by many, that quantization is deformation. In the past 30 years what is now called “deformation quantization” developed and has proved seminal in a variety of domains, from abstract mathematics to modern theoretical physics. The aim of this special “anniversary” issue is to present some developments in that vast frontier area