The Beginners' All-purpose Symbolic Instruction Code is a computer language developed by Kemeny & Kurtz in 1964. Although it is traditionally interpreted, compilers exist for many platforms. While the interpreted form is typically fairly slow, the compiled form is often quite fast, usually faster than Pascal. The biggest problem with BASIC is portability; versions for different machines are often completely unlike each other; Amiga BASIC at first glance looks more like Pascal, for example. Portability problems actually go beyond even the cross platform level; in fact, most machines have multiple versions of incompatible BASICs available for use. The most popular version of BASIC today is called Visual BASIC. Like all BASICs it has portability issues, but it has some of the advantages of an authoring system so it is relatively easy to use.