To: Fisher Mark <FisherM@is3.indy.tce.com> Cc: Daniel LaLiberte <email@example.com>, Tim Berners-Lee <firstname.lastname@example.org>, Subject: Use Web to launch apps (was Re: URL semantics) In-Reply-To: Your message of "Tue, 14 Jan 1997 12:39:00 EST." <32DBC5A9@MSMAIL.INDY.TCE.COM> Date: Wed, 15 Jan 1997 12:52:01 +0000 Message-Id: <email@example.com> From: Zheng Wang <Z.Wang@cs.ucl.ac.uk> We have been looking at similar issues in the Hipparch project. I enclose here a simple description of the on-going work, and would appeciate any comments from you. Cheers Zheng -------------------------------------------------------- In the Hipparch project, we have been looking at issues related to integration of applications into Web. Basically, we would like to use the Web as the standard interface and launch all applications from the Web. Currently, there are two ways of launching an application (either built-in or standalone ones) from the Web: 1) Use URL. For example, ftp://cs.ucl.ac.uk/darpa/hipparch-ucl1.ps mailto:firstname.lastname@example.org telnet://sonic.cs.ucl.ac.uk 2) Use MIME mapping. When an object is retrieved, an application is started to receive the data. An example is ps files: http://cs.ucl.ac.uk/darpa/hipparch-ucl1.ps Although the above mechanisms work fine for some applications, trying to extend them for applications with many parameters (e.g. a video conferening tool) seems to be messy. We dont want to overload the URL too much. Also, the MIME mechanism's "fetch and play" does not work well for real-time applications. We are looking at a simple approach to use the Web as launch pad for applications. We store details about launching an application and its associated paramters into a file, and then point to the file with a URL. When a user clicks the active element representing the URL, the browser fetches the application description file, and starts the application. What we need is a generic description of the application and its sessions in a way independent of platforms and implementations, similar to the Session Description Protocol (SDP) for multimedia applications. The generic description, which we call Standard Application Interface (SAI), can include application name and its paramerters, operations for this session and maybe resource requirements and other information. For example, for a ftp session, we may have a file called hipparch.sai which contains: ---application--- NAME: FTP FTPSITE: cs.ucl.ac.uk USER: anonymous ---session--- GET darpa/hipparch1.ps GET darpa/hipparch2.ps ---resource--- SIZE: 2.5 Mbytes TIME: after 6pm Then we have a URL as http://www.cs.ucl.ac.uk/staff/zwang/hipparch.sai. When a user clicks the URL, the file is fetched and the browser can start the application specific to the platform/implementation.