I’ve been digging around for a few days about Oracle, trying to figure out if another $1 billion-plus acquisition is imminent following yesterday’s news about Oracle buying Taleo for $1.9 billion. Instead, I stumbled onto another piece of news: Workday is currently talking to bankers about going public.

Workday CEO Aneel Bushri told Bloomberg TV last year that he was eyeing a late 2012 IPO, and we’re hearing that’s still on track. We called Bhusri, but he wouldn’t comment for this story.

The bankers I’ve spoken with are blown away by how well the modern-day enterprise software company is doing. When it raised $85 million last October at a $2 billion valuation, All Things D reported that Workday was doing more than $300 million in bookings in 2011, and we understand they blew that estimate out of the water.

But far juicer is the story behind the company. For people who don’t follow enterprise software, Quentin Tarantino couldn’t have scripted this better. Workday was started by Aneel Bhusri and Dave Duffield. The two started PeopleSoft back in the day, and pioneered a rare “nice guy” culture in enterprise software. PeopleSoft was essentially the anti-Oracle and Duffield was the anti-Larry Ellison.

Ellison and Duffield both made billions bringing companies into the modern computing era. But that’s about where the similarity ended. While Ellison was yacht-ing around the world like a playboy, Duffield was starting foundations for no-kill animal shelters and adopting six children. He was the legendary CEO who everyone loved working for, the second coming of Bill Hewlett and Dave Packard. He was Tony Hsieh and the ROI of happiness long before it was a bestselling book.

Then in 2004, Duffield and Bhusri (who is also a partner at Greylock) had to watch as Oracle did the first ever hostile takeover of a software company: Their baby, PeopleSoft. The two were pulled into an epic 11-month drama of PeopleSoft trying to fend off Oracle’s clutches only to end in defeat. Duffield even stepped back in as CEO towards the end in a hail-Mary attempt to keep the company independent. Ultimately, the independent board members voted to sell and the two had to hand over the keys to the company Duffield had taken to calling “the bad guys” during the whole affair. “It was totally depressing,” he told me at the time.

So what did the sixty-something-year-old nice guy decide to do? He and Bhusri were going to do it all again and build a newer, more modern better enterprise software company to go after Ellison in the market. They started on Workday. Best part? They used the $600 million dollars Duffield made off the sale to do it.

I actually wrote the first story on Workday for BusinessWeek back in 2006. Oracle was in the process of swallowing the whole enterprise world whole with a $20 billion acquisition spree and people thought they were crazy. Building a new enterprise software company was like building a new utility. People said there was no way these two had the chops to do it again, in a new modern world. At the time, Bhusri said to me and everyone else: This is a long term game. This will take ten years, and we’ll start to tip in five.

And that is exactly what has happened.

No one talks about Workday– particularly given Greylock’s other hits like LinkedIn, Pandora and Facebook– but they are building the most significant enterprise software company in decades. And it may well turn out to be one of the most lucrative wins in Greylock’s already monster fund since Duffield and Greylock were the sole investors for the first four rounds, pouring some $90 million into the company.

People call enterprise software boring, but companies like Workday matter hugely for anyone who has a job. With apologies to Yammer, Jive, Box and other enterprise up-and-comers, Workday may have the biggest impact on the software running the business world in the coming decade. And it’s a landscape that desperately needs shaking up.

Workday and Salesforce are the two companies that have suddenly knocked Oracle on the defensive, because they are finally– FINALLY– proving that enterprises will rip out stodgy old Siebel and PeopleSoft systems and implement new cloud-based solutions. Oracle is in a catch-22: It wants to push its new Fusion upgrade that has long promised to stitch all this stuff its bought together, but it’s not an easy upgrade. And if companies are going to look at putting in a new system, they’re going to look at Salesforce for the front end and Workday for the back end. That’s an opening Oracle doesn’t want to give them, but at some point, the world will need new software.

For a long time Ellison has controlled all the pieces on the board in one way or another. In addition to Oracle’s dominance and spending spree, Ellison himself invested in companies like Salesforce and Netsuite. But the beauty of the Workday story is that while it’s Oracle’s money funding it– thanks to that PeopleSoft takeover– there is no way Ellison or Oracle benefits from its ascendancy.

There’s another twist of revenge going on here: A handful of bankers I spoke with who are turning bearish on Oracle cite two companies as looming threats. One is Workday and the other is Cloudera. And Bhusri is an investor in Cloudera too, via Greylock. Its CEO is Michael Olson, who sold SleepyCat Studios to Oracle during that same $20 billion-plus buying spree. These are two companies that will never voluntarily sell to Oracle, no matter the price, and they are emerging to be the unstoppable software giant’s first real threats in years. You couldn’t script this long, slow revenge plot better.

It proves that nice guys can finish first. It just takes hundreds of millions of dollars and a little patience.

(Greylock is an investor in PandoDaily.)