GW-Basic
From Computer History Wiki
GW-BASIC, launched in 1983, is a disk-based BASIC language interpreter that was distributed with non-IBM MS-DOS computers, and supports all the graphics modes and features of BASICA.com on computers that do not have IBM Cassette BASIC in ROMs..
GWBasic.exe came with MS-DOS on machines (clones) that did not have Cassette Basic in ROMS.
An excellent reference for GWBasic can be found here:
http://www.oocities.com/KindlyRat/GWBASIC.html
Importantly are: