What is this?

Haystack is a Semantic Web Browser developed by the Haystack Project at the MIT Laboratory for Computer Science and Artificial Intelligence. Itaggregates RDF from multiple arbitrary locations and presents it to the user in a human-readable fashion, with point and click semantics that let the user navigate from one piece of Semantic Web data to other, related pieces.

Haystack's presentation of information is controlled by presentation "recommendations," much like cascading stylesheets, that are themselves described in RDF; such recommendations can be made by a content server, by context-specific "applications" that understand how information can best be presented to meet a particular need, or by a third party offering helpful viewing advice. Haystack offers a rich model of collections to support information gathering and structuring. Haystack's rich presentation layer can display those collections in multiple views (e.g., as thumbnails, Web pages, or taxonomies).

What can I do with this?

You can browse and search arbitrarily complex RDF datasets using different views:

Why was it built?

The Haystack Project seeks to apply semantic web technologies to personal information management. The Haystack system was designed to let individuals manage their information in the ways that make the most sense to them. By removing the arbitrary barriers created by applications that handle only certain information "types", and by recording a set of relationships defined by the developer, Haystack lets users define whichever arrangements of, connections between, and views of information they find most effective.

The Haystack Project and the SIMILE Project are collaborating to produce a stripped down version of Haystack that retains its underlying concepts, but reduces its size and complexity to the bare minimum required to browse and navigate general RDF data.

How do I try it out?

Haystack modules are available as plugins for Eclipse 3.0 running under Linux, Windows, or Mac OS X. We recommend running Haystack only on a sufficiently powerful machine, for example, a Pentium III with a 1Ghz (or faster) processor, 512MB (or more) RAM, and 1GB of free disk space (or more, as your repository grows).

To install Haystack, proceed as follows:

To use Haystack, start Eclipse and select Home from the Haystack drop-down menu that appears in the Eclipse tool bar. Then select Open Perspective > Other > Haystack from the Window menu.

To update your installation of Haystack, proceed as follows:

Is there some documentation?

Yes. See the Haystack Overview for a brief description of Haystack's design principles, as well as an extended illustration of its use. See the Haystack Documentation for usage tips, developer documentation, and more.

Can I see the source?

You can view the Haystack source files using a web browser. You can also download them in one of two ways. If you have a Subversion client, just type

svn co http://simile.mit.edu/haystack/branches/hayloft/source hayloft

at the command line and the latest Haystack distribution will appear in the "hayloft" directory. Alternatively, you can use the Subclipse plugin for Eclipse 3.0, which is available from the Subclipse Update Site.

Licensing and legal issues

The Haystack Core Feature is open source software and is licensed under the BSD license shown during the installation process (and also located in the license file in Haystack core plugin).

The Haystack Subfloor feature contains third-party libraries that are not released under the same license. We are redistributing them untouched. Links to their licenses are shown during the installation process.


This software was created by the Haystack Project under the direction of Professor David Karger. Contributors to the code base include: