Chrome Frame is viable and a solution we push for. The reason is that our product is sold to a variety of customers, some wanting "cutting edge" and keen on aut

Chrome Frame is viable and a solution we push for. The reason is that our product is sold to a variety of customers, some wanting "cutting edge" and keen on automatic upgrades, while others are more reluctant and want a more static panorama (control issues, or 'special' demographics that would be lost on a browser switch), yet both want convenience features like file attachments via drag and drop. We have limited resources, therefore we stay focused on our area of expertise and stick to standards (zero flash/java/silverlight to minimise support area and odds of yet another thing possibly going wrong), develop edge (HTML5, CSS3, responsive...) first, and have fallbacks for less compliant browsers (e.g IE9), and possibly block access to part or entirety of our products to old browsers, while clearly informing the user as to why he should live with it or get on board, and that he can use Chrome Frame to not change anything to his habits but raise the "features" bar (most of the resistance comes from ivory tower project managers and BOFH sysadmins, while users mostly don't care or agree). This is, for us, the only viable solution in the long term.