BBC BASIC was one of the many many BASIC languages, this one however being coupled with the BBC Micro (version 1 & 2). It lived on in RISCOS as version 5 and 6, and grew to feature all sorts of neat addons and was even useful for GUI programming. There's even a web browser for RISCOS written in it called WebsterXL. Compilers were developed for it, but never caught on. A lot of it's popularity was the linked to the fact it was supplied on all machines as an OS module and BASIC programs could be run as if they were executables, with a simple double click. It was also extremely fast (for BASIC).