Some Review

• What might a systems researcher find interesing about the Internet?
• What is switching? What kind of switching does Ethernet use?
• What is an IP address?
• What is DNS? Why do we have it?
• What is a protocol?
  • Standard/protocol versus implementation
• What is TCP? What is the end-to-end argument?
• What is protocol encapsulation?

A (Very) Short History of the Web: 1940s

• Bush, Vannevar; As We May Think; Atlantic Monthly; 1945.
  • Identified problem: human knowledge is so large that using the record of that knowledge is difficult
  • Described an imaginary device called the memex, a tool for augmented memory and association-based information recall
  • Described search, text-based document interconnection, and document annotation

A (Very) Short History of the Web: 1960s

Example of hypertext

Nelson 1965

• Ted Nelson; Complex information processing: a file structure for the complex, the changing and the indeterminate; ACM; 1965.
  • Proposed files that can be reorganized, with change tracking, and document interconnection
  • Coined term hypertext
  • Also "zippered lists"
  • Guess one of the citations in this paper
  • Any epistemologists in the room? Nelson proposes storing knowledge in a non-linear fashion, something we are free to do when abandoning paper: this allows us to reorganize information as meta-information changes
• J.C.R. Licklider and Robert Taylor; The Computer as Communication Device; 1968.
  • The paper you read; we'll talk about it later

A (Very) Short History of the Web: 1980s

• 1980's
  • Email, file transfer, other protocols common on the Internet
  • 1981: Project Xanadu envisioned by Nelson
    • Interactive hypertext
    • Network sale of documents/quotations
  • 1989: TBL proposed World Wide Web

A (Very) Short History of the Web: 1990s

• 1990: first web browser WorldWideWeb and web server httpd (by TBL)
• 1991: Tim Berners Lee's paper on web accepted as poster
• 1993: Continued to refine URIs, HTTP, and HTML

A (Very) Short History of the Web: 2000s

• Does the web achieve hypertext as Nelson described?
• Web 2.0 comes into fashion
• Web becomes layer for applications

Is the Web an Example of Worse is Better?

Cross-Browser Headaches

CSS and JavaScript are supported slightly differently on different browsers (remember the standard/protocol versus implementation issue)

Computer as Communication Device

• How did Licklider propose a computer could mediate communication?
• What did he mean by contrasting switching and interacting?
  • Is there a similar comparison between Internet and Web or applications built on top of the web?
• Who knows what he is talking about when he discusses a time-sharing computer?
  • Time-sharing is important again with web applications!
• What element that later became a part of TCP did he predict?
• What about interroperability? How does that relate to the web?
• General thoughts?

Web 2.0

• Is the "new" web getting us closer to Licklider's vision of computer as communication device?
  • web pages
  • forums
  • blogs
  • wikis
  • twittering
  • annotations?
• Affordances provided by communication tools help shape nature of interaction
• When do these technologies succeed at enabling communication, and when do they fail?
• What about augmenting face-to-face meetings?
• How's the cost model these days?

Structure of a web application