"If you want to protect yourself from big corporations, use the SA clause. That makes sure anyone committed to openness can still use it, from the little people to a big business, but corporations who do not contribute thei work and their improvements back, even for you to use those improvements commercially, won't be able to. And they will always need to add value to it, and share that value with everyone, because the original is already available from you. And if a big business is really open and uses your work, you also get the credit and the economic benefits that come from reputation."