CYCLADES
Quotes from Louis Pouzin that are useful to understand what CYCLADES contributed to the development of the Internet: (this should be rewritten into a real article)
CYCLADES is based on packet-switching, like the Internet. In fact, all started with a report/ratio of Paul Baran (Rand Corporation) who, in 1963, described a reliable network using the communication of packets independent of one another. In 1967, Larry Roberts, who animated the ARPA, launched the project of a computer network allowing to share resources, thus motivating the researchers who could work remotely on their computer, by preserving their usual environment.
The first document on the ARPA network was published in 1968. Thus, basic architecture was known as of this date, on paper, because the demonstration had yet to take place. At the beginning of the CYCLADES project, I went to the United States and was consulting the company BBN, the same one which working with the ARPA project. The ARPA network implemented packages in virtual circuit, our network of packets was "pure", with independent datagrams, as in IP today. IP took from the CYCLADES the "pure" packet and logical addressing and not the physical addressing which was used by ARPANET. I had also introduced into CYCLADES the concept of zone, which one calls field in the Internet, as well as the mulihoming and the concept of window slipping for the control of flow. TCP/IP is thus an improved version of CYCLADES. It adds in particular the possibility of splitting up the packets in the course of route, a little like a train whose wheel base varies according to networks. This concept is very useful to correct local area networks Ethernet, which did not exist when we conceived CYCLADES
[From Interview with Louis Pouzin (Autrans'98)]