Bitcoin was built on the sort of open-source ethos that has driven generations of geeks. But the same principles it celebrates—a decentralized network of contributors, a transparent code base—are allowing competitors to flourish. The bitcoin faithful aren't so sure that's a good thing.

Two high-profile bitcoin developers, Gavin Andresen and Mike Hearn, released an alternative version of bitcoin over the weekend. In software parlance, this kind of offshoot is called a "fork." Hearn acknowledged in a blog post that not everyone is thrilled with the endeavor. "The community is divided," he wrote. "Such a fork has never happened before."