What is MDS and how does it effect the SharePoint browser experience? There is very little documentation around regarding MDS (which stands for Minimal Download Strategy). It appears to be a technology that Microsoft is introducing with the next release of SharePoint (SharePoint 15 / SharePoint 2013). I make this wild assumption as I’ve not heard or found reference to MDS prior to the release of the SharePoint 15 API reference.

In Microsoft’s own words:

The minimal download strategy will use a single .aspx file (start.aspx) for your pages, with the actual URL encoded in the text following the hashmark (‘#’). When navigating from page to page, only the changes between two compatible pages will be downloaded. Fewer bytes will be downloaded and the page will appear more quickly.

At this stage it is unclear as to whether this new MDS technology is specific to certain page types within SharePoint or Microsoft is tackling it at a more fundamental level and it is a technology that may be equally applied to .Net web applications in future.

With the vast UI performance we saw between Server 2007 (MOSS) and SharePoint 2010 thanks in large part to the introduction of AJAX, can we expect a similar performance improvement when SharePoint 15 hits our servers? Until I see it in action I will reserve my judgement, it does make you just a little bit excited though doesn’t it…

SharePoint 15 Technical Preview Interoperability API Documentation

EDIT – Now that SharePoint 2013 Preview is available the best article I’ve come across on the workings of MDS is this article from Wictor Wilen SharePoint 2013 – Introduction to the Minimal Download Strategy (MDS)