a) There are a bunch of open source tools that are not well supported on windows. So somewhere along the way you might run into software that you need but doesnt work out of the box on windows. b) Linux distros have package managers which make the task of setting up development libraries a breeze. On windows youre still stuck installing each library by hand. c) If what youre doing is very well defined and all the technical pieces have windows installers then theres not much of an advantage moving to linux. d) If youre using the windows .net stack then again youre probably better off sticking with windows.

The one thing about Linux is that you have full control. When you're with Windows or any other closed source system, you have to issue bug requests to the company to fix it. And chances are that they might not fix it. With open source, you'll just need to find someone smart enough to fix it. There's also limitless possibilities in terms of customization of the technology to suit the system you're trying to build. For that, I would pick Linux. And yes.. package managers and unix tools make it a breeze to deploy.