Probably not as professional as the other answers, but if one just wants to see how IE is rendering the site, the following options are free and work without any heavy installation:

 - Google Chrome Extension **IE Tab** (Windows only)

 - Google Chrome Extension **IE-On-Chrome**

 - https://netrenderer.com/

 - http://browsershots.org/

Note that none of them work locally (i.e localhost or 127.0.0.1).

Similar questions were asked in SO ([here](http://stackoverflow.com/questions/3426498/online-internet-explorer-simulators) and [here](http://stackoverflow.com/questions/3844682/is-there-a-ie-tester-for-mac)), but they are pretty old and the topics are closed.