Microsoft and Apple Computer are the yin and yang of the computer world. Without either of them, the technology landscape would not be as it is today. At the head of those two very different, but significant companies are equally different and significant individuals: Bill Gates and Steve Jobs.

The two pioneers are often at the center of the stage preaching the latest innovations for their respective companies, but rarely do they share the same stage. Bill Gates and Steve Jobs appeared together at this year’s D: All Things Digital conference, an annual gathering coordinated by the Wall Street Journal.

The session began with each leader asked to say what the other has contributed to the industry. Jobs started, “Well, you know, Bill built the first software company in the industry and I think he built the first software company before anybody really in our industry knew what a software company was, except for these guys. And that was huge. That was really huge. And the business model that they ended up pursuing turned out to be the one that worked really well, you know, for the industry. I think the biggest thing was, Bill was really focused on software before almost anybody else had a clue that it was really the software.”

Then Gates started with a joke, “First I want to clarify, I'm not Fake Steve Jobs,” referring to the notorious blog. “What Steve's done is phenomenal. Back in 1977, the Apple II, the idea that it would be a mass-market machine and an incredibly empowering phenomenon. And the Macintosh, that was so risky. Apple really bet the company, Lisa hadn't done that well, but the team that Steve built within the company to pursue that, some days it felt a little ahead of its time. Remember the Twiggy disk drive and...” – Jobs interjected, “128K!”

Gates continued, “In a certain sense, we build the products we want to use ourselves. He's really pursued that with an incredible taste and elegance and had a huge impact on the industry. Apple literally was failing when Steve went back and reinfused innovation and risk-taking that have been phenomenal. So the industry has benefited immensely from his work. I'd say he's contributed as much as anyone.”

The two then went over some historical bits, arriving eventually to 1997, when Steve Jobs returned to Apple. Jobs recalls his thoughts from that time, recorded by the D5 website, “If the game was a zero-sum game where if Apple wanted to win, Microsoft had to lose, then Apple was going to lose. But Apple didn’t have to beat Microsoft. It had to remember what Apple was. Microsoft was the biggest software developer around, and Apple was weak. So I called Bill up.”

Although Bill Gates and Steve Jobs are popularly portrayed as rivals, especially in the movie the Pirates of Silicon Valley, the Apple leader says that his company’s close ties with Microsoft is very important. “The developer relationship between Microsoft and Apple is one of the best we have,” said Jobs.

A bit of a rivalry does appear on the topic of the Mac ads that appear all over the web and television. Bill Gates referred to the ads as lies in an interview back in February, “I don't know why [Apple is] acting like it’s superior. I don't even get it. What are they trying to say? ... Does honesty matter in these things, or if you're really cool, that means you get to be a lying person whenever you feel like it? There's not even the slightest shred of truth to it.”

Back on stage, Job defended the purpose of the ads, saying, “The art of those commercials is not to be mean, but for the guys to like each other. The PC Guy is great… The PC Guy is what makes it all work.”

Gates had only to say, “PC guy’s mother loves him.” The two hosts of the session chimed in to add that they liked PC guy too.

Moving away from current spats and towards the current products, Jobs cited Alan Kay as once saying, “People that love software want to build their own hardware.” Although Microsoft has its own hardware devices with the Xbox consoles and the Zune, Jobs is referring to any potential desire Microsoft may have to build machines specifically to run Windows.

One of the forum hosts had brought up an interesting anecdote: at one point, Microsoft was for a while the biggest purchaser of a certain Mac tower for the use of Xbox 360 development software. Gates then added, “I don’t know if it was the biggest, but, yeah, we had the same processor essentially that the Mac had. This is one of those great ironies is they were switching away from that processor while the Xbox 360 was adopting it. But for good reasons, actually, in both cases. Because we’re not in a portable application and that was one of the things that that processor road map didn’t have. But yes, it shows pragmatism, but we try and do things that way. So that was the development system for the early people getting their software ready for the introduction of Xbox 360.”

Jobs then shifted the attention to Apple’s leading hardware innovation, the iPod, and a key reason why it is so successful. “If you look at the reason that the iPod exists and the Apple’s in that marketplace, it’s because these really great Japanese consumer electronics companies who kind of own the portable music market, invented it and owned it, couldn’t do the appropriate software, couldn’t conceive of and implement the appropriate software. Because an iPod’s really just software. It’s software in the iPod itself, it’s software on the PC or the Mac, and it’s software in the cloud for the store. And it’s in a beautiful box, but it’s software.”

Jobs and Gates were both there at the modern computer revolution, and they are still here today, furthering progress. “When Bill and I first entered the industry, we were the youngest guys in the room, and now we’re the oldest. I tend to think of things in terms of either Dylan or Beatles songs. And there’s that one line in that Beatles song, 'You and I have memories longer than the road that stretches out ahead,' and I think that’s clearly true here,” concluded Jobs.