A Call For Help

Dylan is a multi-paradigm functional and object-oriented programming language. It is dynamic while providing a programming model designed to support efficient machine code generation, including fine-grained control over dynamic and static behaviors.

Dylan is (and was) a vision of a different world: one with the flexibility of Smalltalk, the power of Lisp, while still allowing for compilation to efficient code.

During the 1990s, multiple teams of people at Apple, Carnegie Mellon University, and Harlequin (defunct makers of LispWorks, now a product of Xanalys) created and worked on Dylan for many years. Dylan fell by the wayside when its sponsoring organizations ran into financial troubles, and has been maintained by an open source project over the last decade as “Open Dylan”.

Open Dylan is the open source adaptation of the commercial Dylan tools that were developed at Harlequin. Open Dylan has a very sophisticated compiler, tools and IDE (although the IDE and some of the tools are currently Windows only). These tools were truly amazing for their time. Open Dylan is preserving, maintaining, and enhancing this powerful programming language.

We believe that Dylan has value in terms of the history behind it, the philosophy of the language design, and the unique perspective it provides for solving modern-day software engineering problems. The Open Dylan project brings all of these capabilities together in a free, open-source project that anyone can use.

Learn how to get started with Dylan by visiting https://opendylan.org/download/.

We have a number of projects where we currently lack the knowledge, experience, or available people to begin or complete them. This isn’t to say that we’ve been idle! We’ve been improving performance of our core libraries, optimizing our HTTP code, creating a stand-alone binary-data library and many other things.

We’re making a call to the community of interested people to say that we’re more than willing to help people get started with Dylan and to help deal with problems that arise in the course of making progress on some of our open projects.

We have a partial list of open projects in our wiki, but we’d like to call special attention to a subset of them.

If you’re interested in any of the below, please get in touch with us via our mailing list, IRC or ping us on Twitter. If none of the projects below sound interesting, feel free to check out the list on the wiki to see the others.

Read on to see how you can help!

Cocoa Bindings

We’ve recently made substantial progress on our Objective C / Dylan bridge and the development branch of our compiler will soon support sending Objective C messages. With this, we can begin to wrap the Mac OS X Objective C APIs, in particular those for creating GUI applications.

Our current Objective C bridge lets us do things like:

let c = objc/get-class("NSObject");
let s = objc/register-selector("alloc");
let o
  = primitive-wrap-machine-word
      (%objc-msgsend (c.as-raw-class, s.as-raw-selector)
         () => (obj :: <raw-machine-word>)

We will make this simpler and provide bindings for core Cocoa libraries so that programming experience is more pleasurable and less verbose.


DUIM is the Dylan User Interface Manager. It is a cross-platform GUI library that inherits some of the design from Common Lisp’s CLIM and descends from the Symbolics Open Genera Lisp Machine OS.

Despite being built to be cross-platform, the only currently fully functional backend for DUIM is the Windows version.

Improving DUIM and making it available on additional operating systems is key to the future of the Open Dylan IDE (which is currently only available on Windows).


DUIM currently runs on Windows, but it is quite dated and doesn’t fully respect modern interface standards. The port needs to be updated to properly use the theming mechanisms available.


We would like to have a Cocoa backend to DUIM. This work has not yet been started and would need to progress in parallel with the creation of Cocoa bindings for Dylan.


We have a good start on a GTK+ backend to DUIM in the Open Dylan repository, but it needs a good bit of work, especially from someone that knows GTK+ well.

Extensive work was done in this area during the summer of 2013, when we created a full set of bindings for GTK+-3.0 and related APIs.

Code Mirror Editor Support

Code Mirror is a great editor that runs in the web browser. It is written in JavaScript and supports over 60 languages. It is also a key element of the Light Table IDE.

We’d like to have Code Mirror support for Dylan. This would initially involve correcting our existing syntax highlighting and then moving into further improvements like supporting auto-indentation and other Code Mirror features.

This would involve writing JavaScript code.

Networking Library

We need to add IPv6 support to our networking library.


We need assistance with packaging on pretty much every operating system / distribution apart from FreeBSD, Gentoo Linux and ArchLinux. We would particularly appreciate support in producing Debian, Ubuntu, and Mac OS X Homebrew packages.

Our Windows installer also needs some support, particularly in the bundling of the PellesC compiler to improve the first time experience for Windows users.