https://devzone.nordicsemi.com/f/nordic-q-a/1351/how-do-you-download-versions-of-the-nrf51-sdk-older-than-5-x-xIt seems like it should be easy, but I&#39;ve spent a fair amount of time and haven&#39;t found a way. I only see options 5.0.0 and 5.1.0. There are also links to earlier SDK versions in the developer zone comments, but they all appear to be stale.en-USTelligent Community 13Mon, 22 Sep 2014 12:37:40 GMThttps://devzone.nordicsemi.com/thread/6147?ContentTypeID=1Mon, 22 Sep 2014 12:37:40 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6e55e4eb-098c-4461-aacb-b74264878812Asbj&#248;rn<p><a href="https://www.nordicsemi.com/eng/nordic/Products/nRF51822/nRF51-SDK-zip/23446">Previous SDK downloads:</a></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/6146?ContentTypeID=1Tue, 14 Jan 2014 22:58:39 GMT137ad170-7792-4731-bb38-c0d22fbe4515:540ca6bf-0127-4c97-9172-26279a5b41e5Richard von Lehe<p>And to answer my own question, the download for 4.4.1 is available for the installer, just not the zip (which is what I was trying to get).</p><div style="clear:both;"></div>