The door is, and has been, open for anyone to produce a rival. There are plenty of large corporations with the cash to make an offering and several have tried. So far, the alternatives with the exception of Linux have been crap IMO, and the market has rejected them. If Asian govts produce an alternative it will be a product designed by a committee and will not win. But it will probably dent MS profits considerably just by being an inferior alternative.
Shows how really really stupid the DOJ was to incite so much hatred against a company that has done so much for USA.
By the way, I am not American and I am short MSFT. Other countries are laughing at the US for shooting itself in the foot over the MS anti competitive action, and now the EU is set to get some free money from a similar procedure at America's expense. If I were Bill Gates I would put one finger up and set up in Canada or some other country. Maybe the fact that he didn't do that shows him to be a man that stands behind his country even when it has stabbed him in the back. Good for him!