Berkano's original name was SWAF. This name was an accronym for Simple Web Application Framework. For the directions taken by SWAF were not to be yet another framework, and also because "swaf" brought up a number of irrelevant but it-related google results, it was decided the name should be changed.
A funny brainstorm with a couple of friends.. was fun but did not give satisfying results. However, ChrisBK suggested I use a rune name, because their names are usually pretty catchy and makes one look smart. (Mind you, that's how he found a name for one of his pet projects)
Berkano is the name of the rune of the birch goddess:
it is the container of all becoming/being. It is a collector and conserver of energy and a sign of enclosure and shelter.
So, all in all, there's no real reason, but I tried to select of the runes whose meaning was closest to community related concepts, since Berkano's component evolve around those too. (Users, preferences, website navigation, ...)