Caching in the World Wide Web is based on two critical assumptions: that a significant fraction of requests reaccess resources that have already been retrieved; and that those resources do not change between accesses. We tested the validity of these assumptions, and their dependence on characteristics of Web resources, including access rate, age at time of reference, content type, resource size, and Internet top-level domain. We also measured the rate at which resources change, and the prevalence of duplicate copies in the Web. We quantified the potential benefit of a shared proxycaching server in a large environment by using traces that were collected at the Internet connection points for two large corporations, representing significant numbers of references. Only 22% of the resources referenced in the traces we analyzed were accessed more than once, but about half of the references were to those multiplyreferenced resources. Of this half, 13% were to a resource that had been modifi...

In this paper, we study the problem of constructing and maintaining a large shared repository of web pages. We discuss the unique characteristics of such a repository, propose an architecture, and identify its functional modules. We focus on the storage manager module, and illustrate how traditional techniques for storage and indexing can be tailored to meet the requirements of a web repository. To evaluate design alternatives, we also present experimental results from a prototype repository called WebBase, that is currently being developed at Stanford University.

Source code browsing is an important part of program comprehension. Browsers expose semantic and syntactic relationships (such as between object references and definitions) in GUI-accessible forms. These relationships are derived using tools which perform static analysis on the original software documents. Implementing such browsers is tricky. Program comprehension strategies vary, and it is necessary to provide the right browsing support. Analysis tools to derive the relevant crossreference relationships are often difficult to build. Tools to browse distributed documents require extensive coding for the GUI, as well as for data communications. Therefore, there are powerful motivations for using existing static analysis tools in conjunction with WWW technology to implement browsers for distributed software projects. The chime framework provides a flexible, customizable platform for inserting HTML links into software documents using information generated by existing software analysis tools. Using the chime specification language, and a simple, retargetable database interface, it is possible to quickly incorporate a range of different link insertion tools for software documents, into an existing, legacy software development environment. This enables tool builders to offer customized browsing support with a well-known GUI. This paper describes the chime architecture, and describes our experience with several re-targeting efforts of this system. 1

The constantly growing and changing nature of certain information sources creates new problems in presenting it to the user. While it may be desirable to maintain awareness of changes to this information, it is typically not a person's primary task. This article describes how animation can be used to communicate dynamic information in a limited space and with limited disruption to the user. We focus on a study on the preferences and reactions of twenty-five participants to tkscore, an application that presents NCAA Tournament game scores using a variety of different animated displays. Results from the study are provided along with future research directions.

The Internet has the potential to deliver information to communities around the world that have no other information resources. High telephone and ISP fees - in combination with low-bandwidth connections - make it unaffordable for many people to browse the Web online. We are developing the TEK system to enable users to search the Web using only email. TEK stands for "Time Equals Knowledge," since the user exchanges time (waiting for email) for knowledge. The system contains three components: 1) the client, which provides a graphical interface for the end user, 2) the server, which performs the searches from MIT, and 3) a reliable email-based communication protocol between the client and the server. The TEK search engine differs from others in that it is designed to return low-bandwidth results, which are achieved by special filtering, analysis, and compression on the server side. We believe that TEK will bring Web resources to people who otherwise would not be able to afford them.

this document.

this paper we consider a Web application (or simply an application), as a Versus client with the ability of executing a task through parallel data processing. Therefore each application should be composed by a group of independent threads

AIDE/WN is a tool for automating the "What's New?" page found on many websites, to customize the display of new pages for each user. It uses cookies, something that is already common for other purposes, to identify a particular user across visits and to track the versions of each resource that the user sees. It uses the Htmldiff tool to display the specific changes on request, and at the option of the web administrator, permits users to view the version history of a page.

We present Riptide, a distributed, cooperative Web caching system. Riptide distributes nodes throughout the infrastructure to serve and manage Web content. Riptide is constructed on the OceanStore distributed storage system and inherits OceanStore's scalability and self-con guration. Nodes may be added or removed as desired. New resources are integrated and begin serving requests automatically; attempts to access unavailable resources are transparently routed to alternative providers. Because the underlying system supports mobile data, copies of content may be moved without expensive directory update protocols. Consequently, the load of serving documents may be quickly redistributed to any of the nodes in the underlying system. We describe the architecture of Riptide and present a preliminary performance evaluation of the implemented system running under a simulated workload. 1

Due to its open characteristic, the Web is being posted with vast amount of new information changes continuously. Consequently, at any time, it is conceivable that there will be hot issues (emerging topics) being discussed in any information area on the Web. However, it is not practical for the user to browse the Web manually all the time for the changes. Thus, we need this Emerging Topic Tracking System (ETTS) as an information agent, to detect the changes in the information area of our interest and generate a summary of changes back to us regularly. This summary of changes will be telling the latest most discussed issues and thus revealing the emerging topics in the particular information area. With this system, we will be ‘all time aware ’ of the latest trends of the WWW information space. q 2005 Published by Elsevier B.V.