I just tried to download a copy of a worksheet from a MaplePrimes posting. The file has a .mw extension and does contain a Maple worksheet. However, when I clicked on "download the worksheet" (or words to that effect) I saw the raw worksheet file displayed in my browser - I would prefer to have the worksheet open in Maple (or allow me to save it to my local disk).
The HTML code that provided the link to the worksheet was created automatically by the "convert worksheet" utility available within MaplePrimes (http://beta.mapleprimes.com/mwconvert/).
My conjecture is that the MaplePrimes server is not sending out .mw files with a MIME type that allows my browser to recognize it as a Maple worksheet. I believe the correct MIME type is application/maple.
If this diagnosis is correct, it can probably be fixed by adding one line to a configuration file and restarting the server.