With the introduction of Microsoft SharePoint 2016, Microsoft are no longer providing a free version of SharePoint. Will that mean that it won’t be possible to download the last free version of SharePoint (which is SharePoint Foundation 2013) once SharePoint 2016 is available? I don’t know. Either way, just to be safe, I recommend that you download SharePoint Foundation 2013 while it’s still available for free, because at some point it may become discontinued and no longer available to download.