Microsoft Reciprocal License (Ms-RL)
On December 9, 2005, the Ms-RL license was submitted to the Open Source Initiative for approval by John Cowan. OSI then contacted Microsoft and asked if they wanted OSI to proceed. Microsoft replied that they did not wish to be reactive and that they needed time to review such a decision.
At the O'Reilly Open Source Convention in July 2007, Bill Hilf, director of Microsoft's work with open source projects, announced that Microsoft had formally submitted Ms-PL and Ms-RL to OSI for approval. It was approved on October 12, 2007 along with the Ms-PL. According to the Free Software Foundation, it is a free software license. However, unlike the Microsoft Public License, it is not compatible with the GNU GPL.