While you're cursing the slow boot times of your modern PC or wondering why you can't have 50 applications open at once without the system taking a hit, cast your mind back to the operating systems of old.

Here are five operating systems we fondly remember. Actually, that's a lie. One of them had us pointing with derision when we first saw it, and even the rose tinted spectacles of nostalgia can't wipe that memory.

OS/2 (1987)

Can there ever have been a more ignominious fall from grace? OS/2 was the love child of Microsoft and IBM, the two brightest stars in the PC pantheon. It had a task switcher, a graphical interface, the HPFS filing system, and lots of other cool stuff. And yet it was utterly destroyed in the market place by ugly, clunky, crashy Windows three point oh.

For the first time, we were forced to confront the appalling truth that marketing always trumps technology. OS/2 never quite died – Banco do Brasil had 10,000 machines running OS/2 Warp in the 1990s – and technically you can still buy it. But don't.

NextStep (1989)

When NeXT computers developed an operating system to run on their proprietary range of computers, the developers were sure that the most important factor for success was for it to contain lots of nerdy technology that would only ever appeal to other developers.

Accordingly, they based it on Unix with a PostScript graphics engine, an object-orientated application layer and built-in Objective-C runtime. They accidentally also included some genuinely cool things, such as 3D widgets, and ironically, this meant that they eventually went on to sire Apple's OS X. No one knows how to capitalise this OS. NextStep, NeXTstep and NeXTSTEP are all officially recognised.

RISC OS (1989)

Developed by Acorn Computers for the Archimedes and Risc PC, the OS was stored in ROM so that it could boot in just a few seconds, yet was modular so that extra features could be patched in from disk. It was the first major OS to use real-time font anti-aliasing and included a much better paint program than MS Paint and a better text editor than Notepad. RISC OS was one of those quirky British things that are much too clever to ever do terribly well. The Marmite OS.

BeOS (1995)

It was supposed to be optimised for multimedia applications which was a bold claim from an OS that shipped with no native video drivers and no multimedia applications. Or any software at all, really. BeOS was also completely unthemable. If you don't like yellow tabs at the top of your windows, you are probably running the wrong OS.

Microsoft Bob (1995)

We've all had this idea at some point. Why not use the rooms in the house as a visual metaphor for the functions of the operating system? So instead of clicking on a calendar icon to open the calendar, you click a picture of an actual calendar on the wall. Genius!

To open the clock, you could click on the clock and to open the web browser you could er, click on the picture of a computer. Or something. Bob "technology" lives on in the form of all those annoying helper avatars in Windows and Office but it remains to this day the only Microsoft product that Steve Ballmer has publicly admitted was rubbish.