OCaml users meeting
Location: Paris, France
Date: Friday 16th April 2010
This year event is a way to meet other OCaml developpers face-to-face and to talk about everything that was done in a year. We hope to have a meeting centered around practical issues in OCaml and reports about projects that had gain some momentum in OCaml world.
Free entry, open to all. Lunch sponsored by CAML consortium.
The day after participants will be able to meet at another location, for OCaml hacking day.
Subscribe here. Subscription is mandatory, don't forget to tick "Inscription OCAML users meeting" and "Inscription OCAML hacking day" if you want
This program is still under construction. This is only gross estimation of what will be done on 2010/04/16 in Paris.
If you are willing to give us a talk, submit a short description following the example above. If there are too many talks for a single day, we will have to choose among all the talks.
The deadline for submitting talks is Friday 9th April 2009. We have a maximum number of 10 talks. You should consider submitting your talk at least 2 weeks before, so that people who need to make arrangement for travel can have the time to organize their journey.
The length of the talk is 20 minutes and 10 minutes more for questions. If there are not a lot of questions, you will be able to convert some part of the 10 minutes question time into demonstrations and extra explanations.
You should subscribe to OCaml Meeting mailing list to coordinate presentations:
https://lists.forge.ocamlcore.org/cgi-bin/listinfo/ocaml-meeting-organization
Follow the template of the first talk:
OCamlCore.org team is the group of people that takes care of administrative part of OCamlCore.org which is a set of resource provided to the OCaml community like a forge and a planet.
This short talk will present what has been done during the last year on OCamlCore.org. It will also give some possible direction on what this platform can offer to the OCaml community in the next year.
OCaml (as other strongly-typed languages) relies on link-time checks to ensure that type safety is not violated at the borders of compilation units (the infamous "inconsistent assumptions ..." error). Such checks entail very fine-grained dependencies among OCaml objects, which are at odds with the implicit assumption of backward compatibility that is relied upon by common library packaging techniques adopted by FOSS package-based distributions. As a consequence, package managers are unable to prevent users to install a set of libraries which cannot be linked together; in practice, that happen quite often during transitions from one version of the compiler (or of some "core" library) to the next.
We discuss how to guarantee link-time compatibility using package dependencies; in doing so, we take into account real-life maintainability problems such as support for automatic package rebuild and manageability of ABI (Application Binary Interface) strings by humans. We present the dh_ocaml implementation of the proposed solution, which is currently in use in Debian to manager more than 300 OCaml packages.
Ocamlviz was a 2009 Jane Street Summer Project, by the first two authors and supervized by the last three. Ocamlviz is a tool for real-time monitoring of Ocaml programs. It can be used to debug and to profile Ocaml programs, including memory profiling. The talk will include a short demo.
Since 2006 Ocaml is being used as the implementation language for the backend of a commercial people search engine (mylife.com, in the ComScore 100 list). In this talk I'll pick some examples from both the query path and the web crawler, and demonstrate why Ocaml was an excellent choice. The focus will be on the networking code, and on the challenge of running a software 24/7 in an environment where hardware failures happen every day. Software needs to be extremely reliable, and there must be strategies of coping with failing hardwares.
This talk describes the experiences of using Ocaml/Ocsigen in a web startup, and introduces some of the resulting projects, made available to the community as open-source. Most of our attention will be focused on Lambdium and Lambdoc. The former is a basic blogging engine, while the latter is a library offering support for parsing multiple markup languages in Ocsigen applications. Lambdoc is a good example of how Ocaml's type system can be used to ensure that semantically-rich and flexible markup does not produce pathological documents.
More information about these projects can be found on my Ocamlforge page.
React is an OCaml module for functional reactive programming (FRP). It provides support to program with time varying values : applicative events and signals.
This talk will briefly introduce you to the FRP model, show you how React supports it and why you may want to use it in your code.
OASIS, formerly OCamlAutobuild, is a tool inspired from Cabal to ease OCaml software and library distribution. The main point is to be able to quickly write a small description of your project that can be translated to a build system. Then third-parties use it to ease distribution of your library/software starting with this OASIS description:
This talk presents some features of OASIS and how an existing OCaml project can use it.
Since David won't be able to come to the Meeting, this talk is cancelled
If you have ever wished to develop web applications using a high-level, strongly typed, functional language, OPA might be just what you have been looking for. Use one simple language, with one consistent type system for the client, the server and the database, and the compiler takes care of everything else, including client/server distribution and server/server distribution.
In this short talk, we will present briefly the OPA language, the difficulties we have met when developing it using OCaml, and we will of course try and convince you to use it for your next web applications.
Objective Caml's runtime library assumes there is effectively no more than one thread running (with permission to access the heap) at a time, this allows many optimisations for monocore architectures, e.g., concurrent data access is quite simplified: to be allowed to read or to write data in the heap, it has to lock a global mutex. The way it was built makes it not possible to take advantage of now widespread multicore CPU architectures. In our talk we will present our feedback on removing Objective Caml's garbage collector and designing a "Stop-The-World Stop&Copy" garbage collector to permit threads to take advantage of multicore architectures.
Lwt is a library for cooperative threads in OCaml. It provides a new way of dealing with asynchronous IOs, events... With Lwt, threads and context switches are so cheap that you can just create one thread for everything that may take time and combine them using monadic operations.
This talk will introduce you to the concepts of Lwt.
The Collaborative Rendering Farm (the corefarm) is a CPU-cycles marketplace dedicated to 3D artists that need a lot of resources to complete their ray traced renderings but that can't afford to buy a dedicated cluster. Using a simple piece of software, naclys, they can share their CPU when it is idle, earning credits, and request computing power from other users when needed.
The corefarm relies on a desktop grid server written in JoCaml and run through the ocsigen webserver : naclgrid. Thanks to the use of a client side sandbox, the desktop grid is generic (any application that complies to the API can be launched on the grid, even if only the yafaray rendering engine has already been ported) and sharing the computer is quite safe.
The talk will briefly describe naclgrid's architecture and present naclgrid's distribution paradigm.
This talk is canceled due to transportation problems
We will discuss an ORM syntax extension that permits natural storage and queries to various database backends, such as SQLite and Google AppEngine, and some of the other challenges to running OCaml code on cloud computing infrastructures.
This year we move back to Paris. We choose to organize the meeting inside Paris so that subways, railways and airports are easily accessible.
The meeting is on 2010/04/16, avoiding collisions with other important events.
The meeting is located at Hotel Ibis Paris Alesia Montparnasse, 49 rue des Plantes, 75014 Paris.
The lunch takes place in the hotel.
Here is the official menu (in french):
The "buffet d'entrée" content will be defined by the restaurant, but enough choices should be available.
For people that will have dinner in Paris, there are 2 possibilities:
You will have to book by yourself the restaurant, if needed (for group of 5 people and more).
Since the meeting takes place in an hotel, you can book a room there.
A wifi access is available in the conference room. Further instruction for connection will be given before the meeting.
The list of participants is published weekly, taking data from INRIA subscription form. We are limited to 80 participants, we will give priority to people coming from abroad and giving a talk.
Subscription is closed since Friday 2nd April 2010.
We are looking for volunteers, especially a video team and an audio team (recording and checking that the sound is correct).