When Google launched its Linux-based Chrome OS in early 2010 and its Chromebook pilot program later that year, most pundits didn’t quite agree with our own MG Siegler’s premise that Google had dropped a “nuclear bomb on Microsoft.” A few years later, it sure doesn’t look like Microsoft has much to fear from Chrome OS. But despite its slow start, it looks as if the Chrome OS momentum is slowly picking up. Google has traditionally been very quiet about Chromebook sales and mostly focused on very large enterprise and educational installs. That’s clearly also the target market for the Chrome OS ecosystem right now, but when Acer says that its $199 C7 Chromebook now accounts for 5-10 percent of its U.S. shipments, it’s clear that some of those devices must have gone to regular users, too. Read the full story at TechCrunch.