On day two of MIX 2010, Microsoft presented details on the Web browser that will go into Windows Phone 7, explaining that it will be based on the Internet Explorer 7 desktop browser and will replace the IE Mobile 6 browser that was included in Windows Mobile 6.5, the predecessor to the Windows Phone 7 operating system. Key features of the new browser are four-point multitouch functionality, zoom-in and zoom-out using a pinching finger gesture on the screen, and what Microsoft called "deep zoom" for high fidelity closeups.