Vision: Web-centric Computation Today’s Web: a popular computer application ... along with desktop publishing, graphics, spreadsheets, databases, CAD, ... Tomorrow’s Web: a uniform medium for access to services... ...including desktop publishing, graphics, spreadsheets, databases, CAD, ...

New Powerpoint Feature: Web-centric PC... Steve’s Startup Page • Miscellaneous • My stock portfolio • Munich Trip • Textbook I’m writing • Logic simulations • CURL hacking • Tax Reporting • Photography Talks New Powerpoint Feature: Microsoft’s Content Wizard will prepare your entire talk! Books CURL Paper Asia Talk

Technology barriers - Interaction barriers Function - Skill barriers C++, ActiveX,... JAVA Programs Text, Pictures Applets TCL, JavaScript Scripts Evolution involves hill climbing along this curve… Discontinuities discourage it! HTML Sophistication

Asia Talk, 5/97 Steve Ward, MIT LCS Alternative: The Gentle Slope... Evolutionary path for accessible tools CURL (MIT LCS): single language supporting • HTML-like formatted hypertext • Author/programmer semantic continuum • Efficient, native-compiled mobile code • Mobile, extensible type system for metadata Function Of course, we hope for something better. In an ideal world, a single linguistic substrate would allow content of arbitrary variety to be transferred among all platforms at an appropriately high level. The CURL project at MIT’s Laboratory for Computer Science is an experiment which pursues this goal. Its capabilities range from representation of formatted text to complex object-oriented programming, and it strives to offer the simplicity of HTML with power beyond that of C++ or Java. Curl is a “gentle slope” language, so named because it smoothes the function/sophistication curve into a semantic continuum. In doing so, it provides (1) interoperability of content coded at various sophistication levels, and (2) an incremental path by which content providers can evolve their skills. Sophistication

Web-centric user view Web Interaction Model replaces Software installation (dynamically imported) “Applications” File system interaction (transparent caches) Local/Remote distinctions Manuals/documentation Windows 95! Config.sys. Install/Uninstall. FAT filesys. Remote mounts. Software updates. Registry. … … ...

Obstacles & Issues 1. Technical: can a coherent web environment support authors, programmers, developers? 2. Business: do industrial interests promote web-centric evolution? 3. Economic: Can current economic models survive the communication revolution?

Partitioned Community... Developers Bill & Jim Programmers Many of US. Authors People who actually have something to say.

Technology Pressures New Communication level: driving forces Function: assimilation of applications Automatization of content consumption Semantic coherence: consistent language interface over content/scripting/programming communities “Groupware” cooperative environments Promising approaches: Metadata? Objects? Code mobility: security, transparency What will emerge as the Lingua Franca of the web?

Structured, interactive documents...

Automatization: Content Extraction Today: Sophisticated Curl user: • Builds get-quote primitive which automates consumption of some particular web content • Might use extract-html, provided by an even more sophisticated user: {define {get-quote name:symbol}:float {extract-html x:float {get-url {append “www.quote.com/qs/SYM=“ name}} {table ...} {table ... {row “Last” x ...} ...} ...} Eventually: server provides typed CURL stock object

An integrated, coherent web...

Alternative: The Gentle Slope... Evolutionary path for accessible tools CURL: a single language supporting • HTML-like formatted hypertext • Author/programmer semantic continuum • Efficient, native-compiled mobile code • Mobile, extensible type system for metadata Function Sophistication

Asia Talk, 5/97 Steve Ward, MIT LCS CURL: A Gentle-Slope Language for the Web Evolutionary path for accessible tools Steve Ward & David Kranz MIT Lab for Computer Science • HTML-like formatted hypertext • Author/programmer semantic continuum • Efficient, native-compiled mobile code • Mobile, extensible type system for metadata Function Of course, we hope for something better. In an ideal world, a single linguistic substrate would allow content of arbitrary variety to be transferred among all platforms at an appropriately high level. The CURL project at MIT’s Laboratory for Computer Science is an experiment which pursues this goal. Its capabilities range from representation of formatted text to complex object-oriented programming, and it strives to offer the simplicity of HTML with power beyond that of C++ or Java. Curl is a “gentle slope” language, so named because it smoothes the function/sophistication curve into a semantic continuum. In doing so, it provides (1) interoperability of content coded at various sophistication levels, and (2) an incremental path by which content providers can evolve their skills. Sophistication