Is it legal to develop iOS apps on Windows? Is it legal to develop for iOS on a Windows machine? I have researched this on Google, but I do not seem to be able to find a direct answer, yes or no, whether it is legal or illegal to do iOS app development on Windows.

Here is an article that I have found regarding the legal issue (or lack of): http://www.pmbaty.com/iosbuildenv/legal.html

Is it legal to develop iOS apps on a non-Apple hardware such as a Dell or Lenovo machine or any other hardware which is generally made for Windows or Linux? or On vmware? 

With regard to location, I am talking about India, or otherwise non-US resident.
Yes

…it's legal to develop iOS apps on hardware or software other than Macs and OS X respectively as it does not violate the Registered Apple Developer Agreement:


https://developer.apple.com/programs/terms/registered_apple_developer_20100301.pdf


You can develop iOS apps on any platform that you can, using a variety of software available. The legal problems come from running OS X on unsupported hardware, or running pre-release software without being a developer, etc.