Communism, as an ideological umbrella, hasn't failed. Soviet Centralism (later known as Stalinism even though Stalin wasn't much of a theoretician) did collapse, miserably even, due to an insufficient quantity of ideal revolution at its start, which led to widespread corruption, lots of bad shit and about 50 to 60 million (estimates vary) people dead due to either de facto murder or gross mismanagement. That is to say, the so-called revolution was merely a "kill the royal family, take over the government" kind of deal instead of a "true" popular uprising. (the "true" uprising being rather bloody hard to arrange.) Same with the PRC though the actors were different. The same will likely happen in every country where an armed coup by a minority is dressed up in red and yellow.
Still, the USSR did cause the literacy rate in their populace to skyrocket right after the so-called revolution and brought a previously agrarian country to the industrial age at a near-breakneck speed compared to the time the west took. All the while crapping all over mother nature, which of course looks worse in the ex-Soviet Russia because one cannot simply dump decades' worth of nasty shit out there and expect it to disappear like it did in the US over a longer period. Same for the PRC, though their literacy campaign was "aided" by a relentless re-doing (some would say mutilation) of the writing system.
The USSR is long gone these days, first to space or not. The PRC's communist past is just a memory now, the country having reverted to a quasi-communist corporate fascism. They still have a nominally communist party and a governmental power structure that resembles the early days of a soviet-inspired communist state, but you'd have to look far and wide to see anything more than the least necessary lip service to old ideals in those who have actual power.
Me, I'm surprised that Cuba is still in a pretty good shape considering that the US has had a near total embargo on it, including medical supplies and the like, for the past sixty years. Probably has to do with Ernesto having been educated as a doctor. Still, that the nation hasn't totally collapsed gives hope that cooperation with the likes of Venezuela, Brazil and the other soon-to-be leftist states in latin america would give the Cuban populace those liberties back which they still lack.
In short, yeah, 1930s communism (what yanks usually mean with the word, generally for lack of knowledge) is pretty much gone except in the case of some very old stalinists. Then again, 1930s capitalism doesn't exist very much either, though its methods of exploitation are still as prevalent today as they were a hundred years ago.
The world has changed, generations have gone by and communism has changed with the times. Look, for example, to the anarchist movement (no, not the "anarcho-capitalists", they're just a bunch of wankers) and the modern vaguely European left for examples of what communism means today. Most of its proponents will shrink before the appellation, but it is inescapable that the modern left is the current incarnation of Marx & Engels' ideals.
What has become of capitalism and the so-called "liberal democracy" is a subject for a thread on communism's polar opposite, fascism.