Ruby on OS XAn event about building Mac apps with Ruby and Cocoa

Friday May 15, 2009. Amsterdam, The Netherlands.

This spring, visit Amsterdam for a day of conference sessions and informal hacking. Find out how to get started writing Mac apps in Ruby, go in-depth with experienced RubyCocoa developers, and get the latest on MacRuby from the people building it.

We’ve gathered a great collection of speakers from the USA, Japan, and Europe, which are active in the RubyCocoa and MacRuby communities.

This will be a small and intimate conference with sessions in the morning and afternoon, followed by an informal hackfest in the evening. The sessions are at beginner to intermediate level and focus on practical and broadly relevant topics.

The hackfest will be a great way to meet your fellow OS X Ruby developers, give a quick demo, or work together on a project.

Conference venue

Ruby on OS X is being held at Pakhuis de Zwijger, a former warehouse along the banks of the IJ. The venue is a 10 minute walk or a 5 minute tram ride from Amsterdam Central Station.

Book now

The early registration fee is €65 (this will go up to €125 after April 19). You can book your ticket using the form below.

Rich Kilmer

Rich Kilmer

Over the years, Rich has contributed to many projects including RubyGems. He now works on MacRuby and HotCocoa. He also co-founded Ruby Central.

Rich is CEO of InfoEther, a Ruby and Rails consultancy providing everything from code review, private training and mentoring, to development.

Satoshi Nakagawa

Satoshi Nakagawa

A major contributor to both the RubyCocoa and MacRuby project, Satoshi also wrote the very popular LimeChat IRC client.

He’s currently working on various iPhone applications such as LimeChat for iPhone, Wikiamo, and AeroReader.

Eloy Durán

Eloy Durán

Besides major work on RubyCocoa, MacRuby, and Rucola, Eloy also actively contributes to Ruby on Rails and various other projects.

Eloy works at Fingertips where he develops web apps and Mac software.

John Shea

John Shea

Ever since the very first public release, John has been experimenting with MacRuby. He has published lots of useful tips and examples.

John is CTO of Eniso Partners, a boutique investment company using quantitative modelling systems written in Ruby, Rails, and MacRuby.

Manfred Stienstra

Manfred Stienstra

Apart from a steady stream of patches and bugfixes for Ruby on Rails—including major components such as Unicode support—Manfred has released numerous Ruby libraries and developer tools.

Manfred works at Fingertips where he develops web apps and Mac software.

Ninh Bui

Ninh Bui

Together with Hongli Lai, Ninh created Phusion Passenger and Ruby Enterprise Edition, a major contributing to the Ruby on Rails community.

Ninh is CEO of Phusion, a company that offers top of the line IT products and services for high profile clients.

Julian Raschke

Julian Raschke

Fascinated by game development, Julian spends his nights working on the Gosu game development library and its Ruby interface.

By day, Ruby is also his tool of choice in various freelancing jobs.

Koen Bok

Koen Bok

Developer at, and co-founder of Sofa, a software and interaction design company that develops products like Versions, Checkout, and Disco, and helps others design theirs.

Cocoa development can seem cumbersome if you come from a Ruby background, especially where you need to deal with XCode. Rucola makes it easy to follow conventions for application layout by providing generators, offers rake tasks for common jobs, and gives you various other handy helpers.

Eloy will tell you about the philosophy of Rucola and walk you through the development of a simple Cocoa application using Rucola.

LimeChat is a very popular IRC client built with RubyCocoa. It’s fast, stable, and it’s easy to write themes using CSS or YAML.

Based on his experience, Satoshi will give you practical advice for building real-world applications with RubyCocoa.

Even though automated testing has become very popular, it has never really taken off with people building GUI applications.

There are probably two major reasons why GUI developers don’t write automated tests. First, writing tests in a traditional compiled language like C is cumbersome, and secondly, a GUI application is less straightforward to test than a library or a web application.

Using RubyCocoa and MacRuby makes testing a lot easier. Not only for applications written in Ruby, but also for regular Cocoa applications written in Objective-C.

Manfred will walk you through the development of a small Cocoa application and show how you can test the various parts.

HotCocoa is a thin Ruby layer that sits above Cocoa and other frameworks. It simplifies the verbose OS X API so that you can programmatically construct user interfaces without Interface Builder.

This works by creating a mapping layer on top of the Objective-C classes. HotCocoa adds Ruby-friendly methods, constants and delegate techniques that look refreshingly simple, but do not prevent full access to the Cocoa APIs.

Rich will demonstrate the current state of HotCocoa, show you how to use it to construct full OS X applications quickly, and what the plans are for the future.

MacRuby allows you to write graphics intensive applications in Ruby because of the close integration with Cocoa. This makes it surprisingly easy to write games in Ruby, especially when you abstract a lot of the plumbing often needed in game development.

John will cover the challenges of using OpenGL, discuss how to build game development tools such as level builders, and present a case study of how he built a side scrolling car game.

Instead of using regular slideware for their RailsConf presentation, Ninh and Hongli decided to write their own Wolfenstein-style raycaster in Ruby using the Gosu game development library.

Gosu has been used for cross-platform, indie game development in Ruby for about five years now.

Ninh will demonstrate RubyStein 3D and talk about why and how they built it. After that, Julian will briefly present the Gosu library and its design philosophy. He hopes to convince you to write a game over the next rainy weekend.

Sofa shipped the first version of Checkout, their point-of-sale application for the Mac, in 2006. Checkout is written in Python using the PyObjC bridge to interface with Cocoa.

Koen will talk about what’s needed to create a great desktop experience on the Mac and share his experiences with building and shipping a commercial Cocoa application that’s written in an interpreted language.

Sold out

We’re very sorry, but registration is now closed.

Your name and affiliation will be printed on your conference badge.

If you like, you can have your Twitter username or IRC handle on your conference badge too.

We’ll send your conference ticket and additional details by email.

Payment processing will be handled by PayPal.

Get a €60 early registration discount

The early registration fee is €65 until April 19, after which it will go up to €125.

What’s included?

Registration includes all sessions, lunch, coffee and tea during the day, and access to the friday evening hackfest. Wireless internet access and 230V outlets will be available.

Questions or concerns?

If you have any questions or special concerns, please email us at