Microsoft have released Rollup 17 for Microsoft CRM 2011.

The build number of this release is 5.0.9690.4150. You must have Microsoft Dynamics CRM 2011 Update Rollup 6 (build 5.0.9690.1992) or a later version of Microsoft Dynamics CRM 2011 installed to apply this update rollup.

As well as over 60 bug fixes, Microsoft Dynamics CRM 2011 Update Rollup 17 introduces compatibility with Internet Explorer 11 when it runs in Windows 8.1 or Windows 7.

This includes the following supported configurations:

The web application when it runs in Internet Explorer 11 on a Windows 8.1-based or Windows 7-based computer

Microsoft Dynamics CRM for Outlook (CRM 2011 client) when run in Office 2013 in Windows 8.1

You can download Rollup 17 here and view the knowledge base article here

We maintain a list of all rollups on our Microsoft CRM 2013 Resources page.