Polyconf 2017

by Julien Kirch, July 9, 2017

Polyconf 2017 is a conference about programming languages and polyglot approach to software development. The 2017 instance just took place so here’s a few subjective words:


I enjoyed the conference: I liked most of the talks, the organisation was solid, and I met a few interesting people.

My pet peeve: several presenters doing the same "Erlang explained in 5 minutes" thing in their talk.

After all these years, it’s still strange for me to see people explaining "I’m so happy to be paid to work with my tool of choice" (yep: it’s usually Haskell), I wonder if it happens in other industries.

Nowadays, thanks to fast machines, using a slow language is not a problem for most use cases, productivity is much more critical. But it seems that all languages are working hard to use advanced techniques like JIT to become faster.


LLVM seem to have become the de facto standard for writing your own language. Seeing how a single project is making simpler to innovate in this field is really cool.


As expected, Rust is all the rage. An interesting use case for it mentioned several times is FFI, when you speed up some critical parts of a program written in a dynamic language running in a VM by calling code written in another language like C. In this case, bugs or strange behaviors in the "fast" language can crash or badly impact the VM. When you’re supposed to have a rock-solid VM like the Erlang one, it sucks!

In this case, using Rust instead of C as the fast language decrease the risk of have a memory or threading bug, decreasing the risk of using FFI.


In most of the big companies I work for at Octo, REST API is mostly the only game in town to expose services and Richardson is a holy name.

At Polyconf on the other hand, people have a more pragmatic approach:

  • they are happy to mix REST with other tools like Protobuf, and Protobuf’s tooling and performance seems interesting;

  • they are perfectly OK to expose business services and not only resources, and they have good arguments to do it.

There is no spoon

In this presentation, Jameson Hampton explained how to improve your understanding of other people, and preventing burnouts.


Pony is an actor-based language that wants to make concurrent programing simple and fast. I liked that he clearly explained that Pony is designed for some use cases, and should probably not be used in other cases.

I loved that, since Pony’s syntax is pretty classic and not a selling point of the language, he skipped this topic in the talk so he could spend more time on the other parts.


"ZetaVM is a Virtual machine and JIT compiler for dynamic programming languages. It implements a basic core runtime environment on top of which programming dynamic languages can be implemented with relatively little effort."

It relies on LLVM and has interesting design choices, like a textual representation for the code packages, you should have a look at it.

Creating and maintaining your own programming languages

Some good lessons from Lokad who created its own programming language to write business rules.

Being the sole user of the languages enabled them to use interesting approaches.


From what I understood the GraalVM project is to two parts:

  • enable the Oracle JVM to compile code at runtime

  • write custom module for several languages (R, Node.js, Ruby) that leverage LLVM to parse the code in this language to generate bytecode that is injected into the JVM

This way all the code in different languages is transformed in the same bytecode so the JVM can do trans-languages optimizations, like inlining.

The idea is interesting and the announced results are promising.

It’s sad that it’s an Oracle project, because their business practices make them untrusty as hell.

Furthermore, if their Ruby or Node.js implementations take traction, they could be in position to influence these languages. When I see the way they manage Java and other projects they are or they were involved in like MySQL and Hudson, I think that could be a very bad thing for these languages.