When we think about invention, we might think about the traditional institutions where innovation tends to happens. For instance, individual inventors or research and development departments and labs. But as Robert C. Allen points out,1 there is in fact another institution, wherein innovations occur as a result of the efforts of a number of people and in an incremental way. Nowadays, and for a large part due to the Web, collective invention has become ubiquitous and might go by different names like open-source in software. What I think is intriguing is that this idea can actually be traced to at least as far back as the 19th century.