Some of the people here are web developers.
We need to test our projects in IE.
Of course I personally use another browser!
I don't know that there's much choice except to have Windows running either dual boot or in a virtual machine. I have a multi-boot setup but I suspect it'd be quicker if you need to switch between OSs frequently to have a VM.
I don't think IE 10 will work in Linux but I used PlayOnLinux to set up Internet Explorer 8 and got it working. They have it as one of the pre-configured applications you can install within PlayOnLinux. I found it worked out ok. YMMV though and sometimes it could end up a corrupted window or crash. They also have pre-configured IE 6 as well, I think. You will need WINE installed, of course.
Here's my tutorial on setting up a PlayOnLinux virtual drive. Then you just instead of clicking the "install non-listed software" click on the "internet" icon at the top and find Internet Explorer in there.
I found that installing IE from the "internet" icon in PlayOnLinux lets you actually connect IE to the internet and use it as a normal web browser.