The sea-change brought on by Wittgenstein's unpublished work in the 1930s centred largely around the idea that there is nothing wrong with ordinary language as it stands, and that many traditional philosophical problems were only illusions brought on by misunderstandings about language and related subjects. The former idea led to rejecting the approaches of earlier analytic philosophy--arguably, of any earlier philosophy--and the latter led to replacing them with the contemplation of language in its normal use, in order to "dissolve" the appearance of philosophical problems, rather than attempt to solve them. At its inception, ordinary language philosophy (also called linguistic philosophy) had been taken as either an extension of or as an alternative to analytic philosophy. Now that the term "analytic philosophy" has a more standardized meaning, ordinary language philosophy is viewed as a stage of the analytic tradition that followed logical positivism and that preceded the yet-to-be-named stage analytic philosophy continues to be in (Rortyian neo-pragmatism and Kripke-esque philosophy).
Although heavily influenced by Wittgenstein and his students at Cambridge, ordinary language analysis largely flourished and developed at Oxford in the 1940s, under Austin and Gilbert Ryle, and was quite widespread for a time before declining rapidly in popularity in the late 1960s and early 1970s. It is now not uncommon to hear that "ordinary language philosophy is dead". Wittgenstein is perhaps the only one among the major figures in this vein to retain anything like the reputation he had at that time. On the other hand, the linguistic turn remains one of most important and controversial movements in contemporary thought, and many of the effects of this turn, which are felt across many academic disciplines, can be traced to ordinary language philosophy.
For example: What is reality? Philosophers have treated it as a noun denoting something that has certain properties. For thousands of years, they have debated those properties. Ordinary Language philosophy would instead look at how we use the word "reality". In some instances, people will say, "It seems to me that so-and-so; but in reality, such-and-such is the case". But this expression isn't used to mean that there is some special dimension of being that such-and-such has that so-and-so doesn't have. What we really mean is, "So-and-so only sounded right, but was misleading in some way. Now I'm about to tell you the truth: such-and-such". That is, "in reality" is a bit like "however". And the phrase, "The reality of the matter is ..." serves a similar function — to set the listener's expectations. Further, when we talk about a "real gun", we aren't making a metaphysical statement about the nature of reality; we are merely opposing this gun to a toy gun, pretend gun, imaginary gun, etc.
The controversy really begins when ordinary language philosophers apply the same levelling tendency to questions such as What is Truth? or What is Consciousness?. Philosophers in this school would insist that we cannot assume that (for example) 'Truth' 'is' a 'thing' (in the same sense that tables and chairs are 'things'), which the word 'truth' represents. Instead, we must look at the differing ways in which the words 'truth' and 'conscious' actually function in ordinary language. We may well discover, after investigation, that there is no single entity to which the word 'truth' corresponds, something Wittgenstein attempts to get across via his concept of a 'family resemblance' (cf. Philosophical Investigations). Therefore ordinary language philosophers tend to be anti-essentialist. Of course, this was and is a very controversial viewpoint. Anti-essentialism and the linguistic philosophy associated with it are often important to contemporary accounts of feminism, Marxism, and other social philosophies that are critical of the injustice of the status quo. The essentialist 'Truth' as 'thing' is argued to be closely related to projects of domination, where the denial of alternate truths is understood to be a denial of alternate forms of living. Similar arguments sometimes involve ordinary language philosophy with other anti-essentialist movements like post-structuralism.