Venture capital is an industry in which the exceptions are often more important than the rules. For many years, investors believed in a golden rule that software was the key to minting returns, leaving hardware as one of the most underinvested areas of venture. Then things changed as new technologies like 3D printing allowed hardware startups to accelerate their product design, and several large exits like Nest Labs, Dropcam, and GoPro encouraged investors to take a new look into the sector.

So I was deeply interested in our story yesterday that the development platform Xamarin raised $54 million in a series C investment from Insight Venture Partners, among others. Like hardware, developer tools has traditionally been a sector that received very little attention from venture capitalists. The reasons have remained persistent: the market isn’t very large, preventing huge scale; there are only a handful of potential buyers, leading to…