Hello,
Looking on the web, it's not clear. It would have been a help if you'd linked to the actual listing that you purchased from.
However, the product FirST BASIC does appear to be a HiSoft product, and I assume that this is version 1.? of their package, There was a later edition, which was 2.?, and this seemed to use the name HiSoft BASIC.
HiSoft produced a range of language compilers and I bought a number of their products for CP/M, and their packages were usually very good, including the manuals. I was not aware of them doing a BASIC, but my interest was regarding C and suchlike, and I was using an Amstrad PCW, and there were various BASIC languages available already, so maybe there was no need for another BASIC in that market.
I understand that version 2 of the BASIC was heavily based on Microsoft Quick Basic, and HiSoft may have substantially re-engineered an OEM version of that product to add various 'extras' for the ST, incl access to GEM. To what extent these things relate to version 1 as well I cannot tell.
However, I do have the PC version of QB, although a slightly later version) and this system is certainly a compiler, as an option. You can create your prog within the environment, and run it within involving a semi compile. Or you can fully compile to an .EXE which requires a BRUN module, or you can compile to a fully free-standing .EXE - again, it's not clear if these facilities were in FirST BASIC as well.
I'll dig some more if needed.
Geoff