Matt Warren has an excellent Microsoft history lesson in his blog post entitled The Origin of LINQ to SQL which explores how LINQ to SQL (Microsoft's Object/Relational mapping technology with programming language integration) came to be despite the internal politics at Microsoft which encouraged the entire company to bet on WinFS. I'm excerpting a lot of his blog post because I wouldn't be surprised if he ends up taking it down or redacting it later. He writes

LINQ to SQL, possibly Microsoft’s first OR/M to actually ship in ten years of trying, was never even supposed to exist.It started out as a humble Visual Studio project on my desktop machine way back in the fall of 2003
Luckily, it didn’t take me long to get the basics up and running. You see, it wasn’t the first time I’d slapped together an OR/M or modified a language to add query capabilities; having already designed ObjectSpaces and parts of C-Omega so I was certainly up to the task. Fortunately, it gets a lot easier the ‘next’ time you design and build something, especially if it was you that did the designing before and you have the opportunity to start over fresh.
Why didn’t I start with WinFS? After all, it was all the rage inside the SQL Server org at the time. Unfortunately, it was the same story as with ObjectSpaces. They were shipping before us. We weren’t on their radar. Their hubris was bigger than ours. Not to mention my belief that WinFS was the biggest fiasco I’d ever bore witness to, but that’s another story.

Yet, part of that story was the impetus to turn LINQ to SQL into an actual product.

WinFS client API even started out as a complete copy of the ObjectSpaces codebase and had all the same limitations. It just had more political clout as it was being lead by a figure at a higher-point in the corporate org chart, and so it was positioned as part of juggernaut that was making a massive internal land grab. We on the outside used to refer to WinFS as the black hole, forever growing, sucking up all available resources, letting nothing escape and in the end producing nothing except possibly a gateway to an alternate reality. Many of our friends and co-workers had already been sucked in, and the weekly reports and horror stories were not for the weak-of-heart. It eventually sucked up ObjectSpaces too and in the process killing it off so that in WinFS v2 it could all be ‘aligned’.

At that point, those of us designing LINQ got a bit worried. There were not too many in the developer division that believed in the mission of WinFS. As a developer tool for the masses, something simple that targeted the lower end was paramount. ObjectSpaces had been it, and now it was gone. There was still some glimmer of possibility that WinFS v2 might eventually get it right and be useful as a general OR /M tool. But all hope of that was shot when WinFS was pulled out of Vista and its entire existence was put in doubt. Had they immediately turned around and brought back ObjectSpaces, that might have worked, but in the intervening months ObjectSpaces had slipped past the point of no return for being part of .Net 2.0, turnover within the SQL org was spiraling out of control, and most of the brain-trust that knew anything about OR/M had already fled.

That’s when we realized we had no choice. If LINQ was to succeed it needed some legs to stand on. The ‘mock’ OR/M I was building was shaping up to be a pretty good contender. We had co-designed it in tandem with LINQ as part of the C# 3.0 design group and it really was a full-fledged implementation; we just never thought it was actually going to be a shipping product. It was simply meant to act as a stand-in for products that now no longer existed. So, for the sake of LINQ and the customer in general, we took up the OR/M torch officially, announcing our intention internally and starting the political nightmare that became my life for the next three years.

This takes me back. I had friends who worked on ObjectSpaces and it was quite heart breaking to see what internal politics can do to passionate folks who once believed that technologies stand based on merit and not who you know at Microsoft. At least this story had a happy ending. Passionate people figured out how to navigate the internal waters at Microsoft and are on track to shipping a really compelling addition to the developer landscape.

Editor's Note: I added the links to ObjectSpaces and C-Omega to the excerpts from Matt's post to provide some context.