[Haskell-cafe] The end of an era, and the dawn of a new one

Simon Peyton-Jones simonpj at microsoft.com
Wed Dec 5 17:56:02 CET 2012


You'll have seen Simon Marlow's recent announcement (included below):

| Today I'm announcing that I'm leaving Microsoft Research.

Simon Marlow and I have worked together on GHC for nearly two decades.
During much of that time we have shared a cup of coffee every morning
(one cup each, since you ask), to discuss what's going on in
GHC-land.  We had frequent detailed and illuminating debates
about design alternatives. Simon is the absolute master of GHC's
code generation, runtime system, garbage collector, support for
parallel execution, and much else besides.  His sheer programming
skill in rooting out obscure and hard-to-reproduce runtime system
bugs has always amazed me.  He is more than just a great hacker,
of course.  He is a leader in our community, has a strong
publication record, chaired the Haskell Prime committee for a
year, and is sought after for tutorials about parallel

I owe Simon a great debt, as I think we all do, for the care and
skill he has lavished on GHC.  He's not going to disappear
entirely, but he will be spending much less time on GHC than in
the past.  That is a change, but it's a change that was always
going to happen sometime, and while change is sometimes
uncomfortable, it can also open up new possibilities.

GHC is over 20, and like my own children (who are actually all a bit
younger than GHC), that's not a bad time to start to head out into the
world.  Over time, more and more people have started to help with the
task of developing and maintaining GHC.  We'll have to do more of
that.  These days GHC has a very large "surface area" (running on
different platforms, dynamic linking, debugger, profiler, GHCi,
libraries and Cabal, etc etc), and has grown far beyond what any
single person or research group can manage.  

Lest you should wonder, I myself will certainly continue to work on
GHC.  But my job is to be a *researcher*, and I am not well equipped --
in temperament or expertise -- to deal with the myriad complexities of
deployment, upgrade policy, portability, and the like.  Well Typed
(mostly in the guise of Ian Lynagh) will continue to handle some of
these issues, but again there is too much for one person to do.

So we need your help.  Seriously.  Rather than just thinking "GHC
HQ will sort it out", I would welcome you saying "Shall I take
responsibility for X?".  Johan, Bryan, and others offering to be
GHC Performance Tsars is a great recent example.  But don't wait
to be asked: just make an offer if you see a gap or an open
ticket --- and I think there will be plenty of those.
Particularly valuable are offers to take responsibility for a
particular area (eg the LLVM code generator, or the FFI).  I'm
hoping that this sea change will prove to be quite empowering,
with GHC becoming more and more a community project, more
resilient with fewer single points of failure. 

I am going to miss that cup of coffee though.  Thank you Simon!
Facebook is lucky to have you.  

Onward and upward.

Simon (PJ)

| -----Original Message-----
| From: glasgow-haskell-users-bounces at haskell.org [mailto:glasgow-haskell-
| users-bounces at haskell.org] On Behalf Of Simon Marlow
| Sent: 22 November 2012 11:27
| To: haskell; glasgow-haskell-users at haskell.org
| Subject: Leaving Microsoft
| Today I'm announcing that I'm leaving Microsoft Research.
| My plan is to take a break to finish the book on Parallel and Concurrent
| Haskell for O'Reilly, before taking up a position at Facebook in the UK
| in March 2013.
| This is undoubtedly a big change, both for me and for the Haskell
| community.  I'll be stepping back from full-time GHC development and
| research and heading into industry, hopefully to use Haskell.  It's an
| incredibly exciting opportunity for me, and one that I hope will
| ultimately be a good thing for Haskell too.
| What does this mean for GHC? Obviously I'll have much less time to work
| on GHC, but I do hope to find time to fix a few bugs and keep things
| working smoothly. Simon Peyton Jones will still be leading the project,
| and we'll still have support from Ian Lynagh, and of course the
| community of regular contributors. Things are in a reasonably stable
| state - there haven't been any major architectural changes in the RTS
| lately, and while we have just completed the switchover to the new code
| generator, I've been working over the past few weeks to squeeze out all
| the bugs I can find, and I'll continue to do that over the coming months
| up to the 7.8.1 release.
| In due course I hope that GHC can attract more of you talented hackers
| to climb the learning curve and start working on the internals, in
| particular the runtime and code generators, and I'll do my best to help
| that happen.
| Cheers,
| 	Simon

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