These are some of the projects I am, or have been, working on. All open-source programming projects listed below, and many more, are available at my GitHub profile page.

Property-Based Testing in a Screencast Editor

Book cover for Property-Based Testing in a Screencast Editor

Property-Based Testing in a Screencast Editor is a short book on using property-based testing (PBT) within Komposition (described below). It’s based on articles published on this site. While the content is mostly the same, there are few changes bringing it up-to-date. Also, if you’ve already enjoyed the articles, you might want support my work by purchasing this book ($10). Finally, you might enjoy a nicely typeset PDF, or an EPUB book, over a web page.


Komposition is the video editor built for screencasters. It lets you focus on producing and publishing quality content, instead of spending all of your time in complicated video editors. Stop wasting time on manually adjusting clip lengths, building still-frame segments, and dragging clips around, and enjoy a new screencast editing experience.

Komposition is written in GHC Haskell using GTK, GStreamer, and FFmpeg.

Haskell at Work Screencasts

Haskell at Work is a screencast focused on practical Haskell programming. Viewers should have a basic understanding of Haskell, and be eager to learn new ways of working with Haskell. Check out the site and subscribe to the YouTube channel if you want to learn more about Haskell in the wild!


The goal of Hyper is to make use of row polymorphism, and other tasty type system features in PureScript, to enforce correctly stacked middleware in HTTP server applications. All effects of middleware should be reflected in the types to ensure that otherwise common mistakes cannot be made.

PureScript Spec

PureScript Spec is a testing framework for PureScript. I started building it April, 2015, but nowadays it’s maintained by others. It’s inspired by the Haskell testing framework hspec.

The Oden Programming Language

As described at, Oden is an experimental, statically typed, functional programming language, built for the Go ecosystem. I worked on the language for the majority of 2016, rounding off in October. Why I stopped working on Oden is explained in greater detail in the blog post Taking a Step Back from Oden.


During my work at Sony Mobile, I created DataFlow, a tool that renders graphs using a declarative markup. It is built around the DFD format, but also supports sequence diagrams and structured data output. We used it to document our service integrations and security requirements between separate systems, and integrated it in to our bigger documentation workflow.