Marc Andreessen: "That's a big deal, that's a very big deal. It's a very serious commitment for a company. Apple's had this commitment, Microsoft's had this commitment. It's what's called a commitment to backwards compatability. So you have to commit to never break anything. So you load up Windows Vista and it run the original Visicalc from thirty years ago, which was the original killer app on the PC, the original spreadsheet. So that is a long term institutional commitment, that takes a very serious company to be able to do."