Me and my work

I am a software engineer by day, or at least by morning. I studied planetary science at MIT but never went into the field.

I work on the Open Cilk project. Previously I worked for a series of tech startups around Boston, or for the companies that acquired them. I have worked on a signal processing chip, parallel extensions to C++ (at a company acquired by Intel), wireless networking infrastructure, content delivery network, cluster filesystems, compilers, device drivers, and more. I have contributed to GCC, being one of the early members of the EGCS project. See my PDF or plain text resume for more details.

I am neither John M. Carr the campus police officer, who died May 22, 2016, nor Joe Connolly who used to work for RLE and was The MIT database may give you one of those two when you ask for me.

Given the choice I program in OCaml, a functional language in the ML family. In addition to OCaml my jobs have involved C, C++, maybe a dozen different assembly languages, Java, Scheme, Python, and more.


I am a member of the National Motorists Association, the only national group supporting motorists rights and the use of engineering standards instead of politics for traffic control.

MassHighway project list

Speed Limits

My interest in traffic law and policy led me to compile a page of State Traffic Laws related to speed limits.

I have an (incomplete) set of online speed regulations for many Massachusetts cities and towns, and state highways. These are the legal documents authorizing posting of speed limit signs. Towns aren't allowed to just make up numbers because that way lies speed traps. Of course, many ignore the law.

Map (and maps) of Massachusetts speed limits. I need to write some new software so I can make better maps.

Local traffic signs

Don't Think and Drive

``The more you drive, the less intelligent you are.'' -- Repo Man.

Radar trailers can slow down cars, or make them speed up.

Tale Of the Troika by Arkady and Boris Strugatsky has a discussion of thinking and driving.

Books and such

I used to be into board wargames but haven't made much time for that in recent years.

I read science fiction. Fifteen years ago I made a list of science fiction book recommendations. I should update these some day. I occasionally write reviews and brief comments on books I have read. I should also update those some day.

If you like math puzzles, check out this test from George Alec Effinger's novel Death in Florence.

Some book jackets are inspiring. Others are not.


I go outside every day. I like to take pictures of squirrels and mountains. See my Flickr page for evidence of this. Some older pictures are on this MIT page.


I have a list of Massachusetts newspapers known to me (daily to weekly newspapers on matters of general interest; not specialist newsletters or magazines).

This page is simple. Because I like it that way. I used to proudly proclaim it not "Netscape Enhanced", meaning I hadn't tried to make it break if you used the then-new Netscape browser. Likewise I avoid javascript, flash, and flashy graphics. I prefer content to presentation. Please support open standards for the internet.

Comments to John Carr.