Right, I've read that it was mainly those apps (and Lotus-123 being huge [1] even among them) that made the IBM PC and clones (the PC's we now take for granted,

Right, I've read that it was mainly those apps (and Lotus-123 being huge [1] even among them) that made the IBM PC and clones (the PC's we now take for granted, though much more powerful now of course), take off as a product category (i.e. become wildly successful) and sell in the millions (both the hardware and the apps) - right from the early days, the '80's, I mean. IBM released the IBM PC in 1981, I've read, though Apple and others were in the home market from the mid-'70's or so. [1] I read somewhere long ago that it (spreadsheets, and Lotus may have been the first one) replaced what were also called spreadsheets - physical ones used by accountants in the US - large sheets of paper for doing accounting calculations, with maybe many joined together to get more area. So an innovation like a spreadsheet, where you could simulate such large joined-together sheets by scrolling up/down/left/right, was a boon and a huge productivity aid to them, also the fact that you could edit data in-place without overwriting/strikeout, etc. And of course, formulae and automatic recalculation.