I have to point out that F# is licensed under the Microsoft Research Shared Source License Agreement, which isn't an approved OSI license.

http://research.microsoft.com/en-us/um/people/antr/vrr/vrr/l...

They had plans to change to a MS-PL (OSI approved) license but still hasn't happened after 2 years.

On a more practical side, the current license isn't bad, just obscure.