First off, there is a distinction to be made between QBasic and QuickBasic.
QBasic 1.1 is the free QB IDE that comes with DOS, Win3.1 and Win95/98 (check the /oldmsdos folder on the CD's for Win9x). It suffers from the 64k limit as described above, but cannot compile exectuables.
QuickBasic 4.5 is a standalone product, using pretty much the same IDE, but with no memory restrictions (invoke qb.exe with the /ah switch to remove memory restrictions) and the ability to compile to executable.
Modern QuickBasic programmers (yes, we are still around!) have found ways to do many weird and wonderful things with QuickBasic, including a DirectX wrapper, the DirectQB graphics library and, of course, WetSpot.