In long-distance racing, there’s a critical runner known as the rabbit.

The rabbit starts out in the lead, forcing the other runners to maintain a certain brisk pace. But as the race goes on, the rabbit falls back, and the other, stronger runners surge forward and eventually win.

A fascinating new six-part National Geographic series called Valley of the Boom, which premieres Sunday at 9 p.m. ET, focuses on the rabbits of Internet mega-technology.

Before there was YouTube, there was Pixelon, which promised a path to mass-streaming of video.

Before there was Facebook, there was TheGlobe.com, which promised a worldwide network where you could stay in touch with your friends by just clicking your mouse.

Before there was Google Chrome and Firefox, there was Netscape, a platform that promised an easy path to browsing the internet.

Pixelon, TheGlobe.com, and Netscape today are just names on Wikipedia, discards along the path by which the Internet came to dominate the world.

They were not, however, unimportant. They were essential, and Valley of the Boom recounts their stories in docudrama form, combining reflections by some of the real-life people from those companies with a true-to-life re-creation of their rises and falls.

The three stories, which differ greatly from each other, are told in a rapid-fire style that leaves viewers with the rarest of feelings: that six hours may not have been enough to explain all the exhilarating and sometimes disturbing intrigue of the tech world during those crazy 1990s.

Netscape, one of the first companies to understand the full potential of an Internet browser, was also one of the first dot-coms that seemed to be soaring to infinity and beyond.

Even after having a hard time explaining the browser concept to old-school investors, Netscape’s red-hot 1995 IPO instantly made it a major technology player.

Unfortunately, that success also sealed Netscape’s doom, since it elevated the company high enough to come into the crosshairs of Microsoft.

Microsoft wanted the browser world to itself, as it wanted every other part of Internet technology to itself, and it set about to crush Netscape by whatever shady means necessary.

By the time Netscape fought back in the courts and won at least a partial victory, it was too late. Netscape itself was toast. Its real-life CEO James Barksdale (played in the dramatized scenes by Bradley Whitford, top) reminisces about all of this with insight and only a modest level of bitterness.

Some of the sparring between Microsoft and Netscape gets a little geeky for the average viewer, but the general thrust is clear – Microsoft, boys and girls, is not your friend.

Pixelon had a different problem. Its technology for streaming video was a brilliant idea, but the man who founded it, Michael Fenne (played by Steve Zahn) was a con man, a crook, and a wanted fugitive who had surgically altered his appearance after fleeing from fraud and embezzlement convictions on the other Coast.

One of the amusing parts of the “Fenne” story is that the guy often behaved like an obsessed lunatic and no one thought this was a red flag because Internet geniuses were often wacky anyhow.

TheGlobe.com had a third trajectory. It was founded by a couple of college students, naturally, and they too had problems explaining to potential investors what it could do.

Starting with not much more than their lunch money, they eventually launched a wildly successful IPO. Alas, it came just before the dot-com balloon popped. So, like a thousand ideas that weren’t so good and a few others that were, TheGlobe.com imploded.

Valley of the Boom doesn’t treat any of these financial failures as a technological loss. On the contrary, interviewees like Arianna Huffington, Mark Cuban, and AOL’s Steve Case, as well as Barksdale and TheGlobe’s cofounders, argue strongly that these rabbits were essential building blocks on which today’s YouTube, Facebook, and major browsers were constructed.

Netscape’s court challenge to Microsoft, for instance, tied Microsoft’s hands just enough that it couldn’t bully all the Netscape successors out of the market.

Pixelon and TheGlobe.com showed that video could be streamed and people could connect on a common platform.

Valley of the Boom is user-friendly enough so those of us who don’t know code can understand the important parts of what’s going on, as well as the human drama.

It’s got enough carrots to keep you on the track running.