documents have been preserved in paper form and are stored in Stanford University's archives; these provide a valuable record of the evolution of the ARC community from 1970 until the advent of commercialization in 1976. An additional set of Journal documents exists at the Computer History Museum in California, along with a large collection of ARC backup tapes dating from the early 1970s, as well as some of the SDS 940 tapes from the 1960s. The NLS was implemented using several domain-specific languages that were handled using the Tree Meta compiler-compiler system. The eventual implementation language was called L10. In 1970, NLS was ported to the PDP-10 computer (as modified by BBN to run the TENEX operating system). By mid-1971, the TENEX implementation of NLS was put into service as the new Network Information Center, but even this computer could handle only a small number of simultaneous users. Access was possible from either custom-built display workstations, or simple typewriter-like terminals which were less expensive and more common at the time. By 1974, the NIC had spun off to a separate project on its own computer. Firsts All of the features of NLS were in support of Engelbart's goal of augmenting collective knowledge work and therefore focused on making the user more powerful, not simply on making the system easier to use. These features therefore supported a full-interaction paradigm with rich interaction possibilities for a trained user, rather than what Engelbart referred to as the WYSIAYG (What You See Is All You Get) paradigm that came later. The computer mouse 2-dimensional display editing In-file object addressing, linking Hypermedia Outline processing Flexible view control Multiple windows Cross-file editing Integrated hypermedia email Hypermedia publishing Document version control Shared-screen teleconferencing Computer-aided meetings Formatting directives Context-sensitive help Distributed client-server architecture Uniform command syntax Universal "user interface" front-end module Multi-tool integration Grammar-driven command language interpreter Protocols for virtual terminals Remote procedure call protocols Compilable "Command Meta Language" Engelbart said: "Many of those firsts came right out of the staff's innovations — even had to be explained to me before I could understand them. [The staff deserves] more recognition." Decline and succession The downfall of NLS, and subsequently, of ARC in general, was the program's difficult learning curve. NLS was not designed to be easy to learn; it employed the heavy use of program modes, relied on a strict hierarchical structure, did not have a point-and-click interface,