1. 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, ...

2. 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

3. 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

4. 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

5. 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. … … ...

6. 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?

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

8. 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?

9. Structured, interactive documents...

10. 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 “
name}}
{table ...}
{table ... {row “Last” x ...} ...}
...}
Eventually: server provides typed CURL stock object

11. An integrated, coherent web...

12. 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

13. 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