Welcome to the web site for the Curl Project here at the MIT Laboratory for Computer Science. Our entire web site can be accessed through the navigation bar at the left; just click on the boxes on the left-hand side to expand or collapse a section of the table of contents. (If the navigation bar isn't working, try the old-fashioned index instead.)

Curl is a new language for creating web documents with almost any sort of content, from simple formatted text to complex interactive applets.

• Curl provides a rich set of formatting operations similar to those implemented by HTML tags. Unlike HTML, the Curl formatter can be extended by users to provide additional functionality, from simple macros (e.g., to provide a convenient way to switch to a particular font, size and color) to direct control over the positioning of subcomponents (e.g., as in a TeX-like equation formatter). Several packages of useful formatting extensions are currently under development.

• Using a TK-like interface toolkit of interactive components, Curl makes it easy to build simple interactive web pages. One can view interactive objects like buttons or editable fields as extensions to the basic formatting operations provided above -- one uses the same easy-to-learn syntax to create interactive documents as to create regular text documents. There's no need to learn a separate scripting language!

• Other components of an interactive document may require more sophisticated mechanisms than are provided by the interface toolkit. These components can also be developed using Curl since, at its heart, Curl is really an object-oriented programming language. Curl expressions embedded in the web document are securely compiled to native code by the built-in on-the-fly compiler and then executed without the need for any sort of interpreter. Curl provides many of the features of a modern object-oriented programming language: multiple inheritance, extensible syntax, a strong type system that includes a dynamic "any" type, safe execution through encapsulation of user code and extensive checking performed both at compile and run time. Almost all of the Curl system and compiler are written in Curl.