Originally developed for the Mac in 1987 as a result of identifying the need for graphic presentations in a world made possible by Mac's GUI , Powerpoint was subsequently bought over by Microsoft. The window's version came out in 1990 and the world never looked back. If there is a competition for software that can be considered 'omnipresent', Powerpoint would surely come up among the top few contenders. A nice article from WSJ on an interview with the programme's creators.
Surely a blog on Powerpoint cannot be complete without a discussion on its users merits and flaws, but since I'm feeling rather lazy today, I'll refer you to the worst powerpoint slide ever? and the effects of powerpoint on pedagogy.
I do like Powerpoint as a canvass upon which art can be created. I also like the use of Powerpoint as a (with apologies to the WSJ article) as a printing press to write detailed business plans: data-rich landscape documents that are meant to be read, not presented. Presentation slides in my view are best kept sparse!
For historians of Powerpoint, the website of one of the creators Robert Gaskins is full of interesting stuff (including Dilbert) for you to mull over.