Abstract :
J is both a mature and an innovative development in computing, which has far-reaching potential benefits for people such as engineers and financial specialists who need to gain or regain direct control over huge and critical computations that they engage in professionally. Such applications almost always process arrays as opposed to processing cells, which has been the early and persistent norm of mainstream computer languages. J started as a language that demonstrated masterly insight into the nature of array processing. This was then realised as an interpreter, which by any standards was software of near perfection. Most recently, and following similar progress to that of APL (which is in some ways the ancestor of J), enthusiasts with considerable computer skills have integrated J into the wider computing world, so that J is now an entire and widely available computing system, which merits greater awareness than is currently the case.
