The web provides users with a huge number of pages that they can read, but extracting useful and reliable information from these pages can be difficult. Not everything on the web is accurate, and important information on a topic will typically be spread across a large number of pages.

Think Link is a tool that overlays a network of factual claims on top of the existing web. As the user browses the web, Think Link highlights factual claims that are particularly interesting or contraversial. Clicking on such a claim brings up an interface showing sources elsewhere on the web that oppose that claim or are otherwise related.

(Think Link has also gone under the name Mind Mix)

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Mash Maker is a browser extension that understands the meaning of the pages that users browse and suggests ways that it can improve the current page so as to be more useful to the user. Mash Maker relies on users to teach it both how to understand web pages, and also how particular kinds of web page might be improved in interesting ways.

As views a web page, Mash Maker will suggest ways that it can make the page more useful, and suggest these improvements on its tool bar. If the user clicks on the button for such an improvement then Mash Maker will apply it to the current page, potentially using other web sites and remote APIs, and potentially applying widgets that produce new visualizations or compute new data (Figure 6). Mash Maker suggests improvements based on the meaning of the current page, the meaning of pages that the user has recently browsed, and the behavior of other users.

Software Transactional Memory (STM) simplifies the process of writing parallel programs by allowing users to program in terms of atomic sections. Early STM implementations were careful to ensure that they were "non-blocking", meaning that the failure of one transaction cannot cause the failure of others.

We observed that, in most cases, deadlock avoidance is the only case in which it is important for an STM to be non-blocking. This observation allowed us to produce a new implemantion of STM that significantly outperformed all previous STM implementation.

While there was considerable resistance to our algorithm when we first proposed it, most modern STM implementations now follow the principles we put forward.

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Unintended or unmediated data sharing is a frequent cause of insidious bugs in multithreaded programs. SharC (short for Sharing Checker) is a tool that allows a user to write lightweight annotations to C programs to declare how they believe objects are being shared between threads in their program. SharC uses a combination of static and dynamic analyses to check that the program conforms to this specification.

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Memory management bugs, in particular incorrect uses of free, are notoriously hard to debug because the symptoms of the problem show up in a place far disconnected from where the bug actually occurred. For instance, an incorrect free can lead to corruption of a completely unrelated object allocated later.

HeapSafe is a C compiler and runtime library that directly check that a program uses free safely, with time and space overheads low enough (normally below 30%) that it can be used all the time. Furthermore, when HeapSafe does detect an invalid free, it can simply leak the object (and log the problem), preventing the program from failing.

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Ease the migration from a legacy language to a new language by maintaining synchronized editable versions of a program in both the old language and the new language, and propagating any updates between the two sides. This work started out as a separate project but has now been merged into the larger Ivy project.

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Some designs of multi-core processors do not give all cores access to all memory. In order to program such devices, it is necessary to move beyond a shared memory programming model. PacLang uses linear types to allow one to easily pass data between concurrent threads, without needing to introduce shared memory. To make this concrete, we produced a high performance implementation of our language for Intel IXP Network Processors.

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If your father tells you to tidy your room, should you do so? That depends on how dirty it is, how forgetful your father is, and how angry he is likely to get if you don't do it. More generally, in order to decide whether to do some computation, one needs to have an accurate model of its cost, the cost of putting it off, and the likelyhood of it being useful in the future. During my PhD, I designed an implemented a system that could build up a model of these properties at runtime and out-performed the existing static analyses by an average of 20%.