I'm really surprised at how many people in this thread are Windows users frankly. I just presumed that most YC commenters were OS X/Linux people with a few FreeBSD, etc.. OSes floating around.
Two nights ago I went to a "bleeding edge web" meetup. I was really struck by how universal, unspoken, and simply taken as a given it was that modern web development is done on a Unix box. Thus there was no room for any discussion about Windows alternatives, or even explanation for us third-worlders about what role certain tools - that at least I had never heard of - play in the ecosystem. I was completely alienated.
In my experience, some things that Just Work on *nix systems or OS X either plain don't work on Windows or kinda-sorta-work after you do a weird workaround. Not all things, certainly, but enough to be a massive pain in the ass.
Unless you're coding for Windows only (eg C#, .Net, etc), Windows is the red-headed stepchild of development environments. I'm somewhat hopeful that this will start to change with the release of Windows 10.
