It&#x27;s been open source since 2009: <a href="https:&#x2F;&#x2F;blogs.technet.microsoft.com&#x2F;port25&#x2F;2009&#x2F;11&#x2F;16&#x2F;microsoft-to-open-source-the-net-micro-framework&#x2F;" rel="nofollow">https:&#x2F;&#x2F;blogs.technet.microsoft.com&#x2F;port25&#x2F;2009&#x2F;11&#x2F;16&#x2F;micros...</a><p><a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;.NET_Micro_Framework" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;.NET_Micro_Framework</a>