Give me one example where the distribution or usage of an open-source solution is comparable to it's SaaS competitor People misunderstand what open-source really is. There is a selfish reason to maintain open-source projects. Developers are above fixing their own problems when working on open-source. This is the only reason companies and developers invest in open-source.
Hence, the type of projects that become massively successful are components, frameworks or platforms... things that are re-usable for the solutions or apps these developers are creating for their companies. There is real economic value being unlocked there. Recent examples being Docker, AngularJS, etc that are supporting by lots of companies
Creating an app or solution is a whole different ballgame. They are usually side projects because there is little or no incentive for a company to take away resources from building their own apps/solutions, to save a few bucks.