We sell Basecamp and HEY, but mostly we give away all our work for free in the form of open source software. Here are 31 distinct open source releases just over the last five years, all from the crew at 37signals: https://gist.github.com/jorgemanrubia/fc… Pay or free, we make everything for the same reason: We need it, we want it, and we think we've found a better way. And if we do, surely others do, so we do this for them, too.