I'm not sure how many these days would actually choose to run Internet Explorer if not in a corporate setting, but a new app, built on Microsoft's Azure RemoteApp technology, allows running of Internet Explorer on Mac OS X, earlier versions of Windows, Android, and iOS.
Called RemoteIE, the app is intended for developers so they can test their web apps to ensure they are compatible with the version of Internet Explorer in the Windows 10 Technical Preview, but it also means anyone on supported platforms can try it out.
A Microsoft account is required, but sign up only takes a couple minutes. And, since the technology is built on Azure RemoteApp, the RemoteApp client is also required. The RemoteApp client is also available for Windows, Android, iOS, and Mac OS X. Interestingly, there's currently no solution available for Windows Phone.
RemoteIE is only for testing Internet Explorer for Windows 10, so if testing earlier versions of Internet Explorer is required, you'll need to utilize the Modern.IE solution. With Modern.IE you can download Virtual Machines running earlier versions of Internet Explorer running on previous versions of Windows, including XP, Vista, Windows 7, and Windows 8.
Try out ModernIE here: Remote Modern IE