I feel I should start this entry by saying: I am not making this up.
I've spent the last two days, and I will also spend tomorrow, having what I consider to be a unique and somewhat strange experience. I've been visiting Microsoft research. What's remarkable about this is that I was invited there by employees of Microsoft research to work with them on the free software project I work on. Yes, that's right, Microsoft invited me to visit them so that they could help improve a piece of free software.
But wait, it gets better. This piece of free software is, at least in its current form, UNIX only. (chroot plays a key role in the implementation, and AFAIK Windows has no analogous function.) In other words, Microsoft invited me to visit them so that they could help improve a piece of free software which doesn't even run on Windows.
Now don't worry, the world has not gone mad, there is a logical explanation. The software in question was developed as a research project at the (now defunct) Digital/Compaq Systems Research Center. Some of the original developers (including the team leader), now work at Microsoft research. So really they have just offered to spend a few days helping me understand and improve a few tricky parts of the implementation of something they built before they worked for Microsoft, which just happens to have become free software.
But still, when I actually think about what I've been doing the past two days, it seems rather improbable.