Plusieurs personnes ont fait des reproches à F# sur sa licence (qui est pourtant loin d'être abusive). F# est fourni gratuitement avec son code source et n'importe qui a le droit de le modifier et de le redistribuer. Mais il existe quelques restrictions sur la redistribution (entre autres, on n'a pas le droit de revendre F# et Microsoft possède de nombreux droits sur les modifications faites).

Suite à une question sur la mailing-list F#, Don Syme a indiqué :

Around March last year we got permission to release the compiler and library source on CodePlex under MS-PL. We still plan to do so at some point, so my apologies for the delay.

However, in the process of looking at making the source code release, we also got approval to take F# through productization. This has given us a unique opportunity to clean up and simplify the language and libraries and re-jig the Visual Studio tools. I guess it's fair to say that this is occupying all of our attention right now. Many of the results of this on the language side were released in F# 1.9.4.

As a result, we've decided to delay making an MS-PL publication of the source code until that process is complete. There's no really deep reason for this except that each public source code release does take us time.

Pour information, la MS-PL (public license) est une licence libre, approuvée par l'OSI et compatible GPL.