Microsoft continues to improve the tools available for testing IE (finally!) via modern.IE:
- Free virtual machines (download test versions of IE 6 to 11 in VirtualBox, VMWare Fusion and Parellels formats)
- Site scan (parses your site for common coding problems)
- 3 months of free BrowserStack usage (their local testing option is pretty slick)
- Compatibility reports (scans your site for code no longer supported in modern IE)
- Screenshots (see how your site looks in 9 common browsers and devices)
The free BrowserStack access is a great deal and worth visiting just for that.