Note that with the edit and continue appearing in VB he meant the immediate window in VB1, not the C++ feature. Also this didn't really appear with VB1, it most likely "appeared" with the first BASIC Bill Gates wrote (as far as Microsoft is concerned, BASIC had it before MS) as any number-based BASIC was able to both run and edit code at the same time and this was evolved to QuickBASIC/QBASIC's "immediate" pane at the bottom where you could run functions as soon as defined them in the editor and modify the program's code and state by pausing it and then this was passed on to VB1 though a dedicated window that remained there until VB6.