From the by start of Linaro there has been much confusion about Linaro and distributions. Part of this, I'm sure is because Linaro is different from most open source entities which, by and large, are either industry consortiums or distributions or a mixture of the two. So what is the relationship between Linaro and ARM Linux based distributions?
Linaro is an engineering organisation, it's work split between working groups containing engineers from its member companies. These groups are working away on such things as power management, kernel consolidation, ARMv8 and so on. We need to test the code and patches created and, to do that, we need a variety of test software. These we call 'engineering builds', and they are tailored to the engineering work and the testing needed. As an example, we have engineering builds based on Android that are used to test the big.LITTLE power management changes that we're making.