The strategic insight behind Arc was perfect – your browser IS the Operating System, and so we should build a browser that can function as that platform. Arc had pretty good market validation with early adopters, they say that growth was flattened out but IMO that's normal for most products, and it's up to the company to find out WHY growth flattened and then solve that problem. Not kill the product and chase some en…
But, there's a bunch on WebKit and Gecko as well.