: Cineast is a freely available, extensible Web browser which intends to provide an environment for prototyping new client side Internet technologies. Cineast has built-in support for HTML 3.2, fill-out forms, tables and incremental loading of documents. The browser itself uses the interpreted Wafe environment for implementing the high level control structures. The basic functionality is integrated into the Wafe package and coded in C, which means that the browser gains performance from the speed of compiled code while main aspects of the application can still be changed without recompilation. The network functionality is provided through the integration of the W3C Reference Library. The presentation of HTML documents is handled by the new Kino widget class which provides a flexible and extensible mechanism for parsing and rendering SGML like languages.