Hi, I'm Sven Groot. Ookii, pronounced /oːkiː/ (roughly “oh-key”), is Japanese for "big," and my last name means that in Dutch. Here, you can find software projects I've created, links to my publications and other University projects, information about my Let's Plays, my occasionally updated blog, and more.

Latest blog posts


2022-09-20 23:54 UTC

Today, I'm releasing something that I've wanted to release for a very long time. It's a project that I worked on during my Ph.D., and while I don't think it'll be terribly useful to anyone, a lot of work went into it that I want to preserve, even if just for myself.

Ookii.FormatC 2.3

2022-09-14 05:40 UTC

This version comes with an optional new dark mode stylesheet, nullable reference types enabled for the library, the ability to write directly to a TextWriter, C# 10.0 keyword support, and a few minor other features and fixes.

Ookii.CommandLine 2.4

2022-09-06 03:05 UTC

This new version comes with nullable reference type support, a new helper to make parsing easier, more customizability, an easier way to make -Help style arguments, and some bug fixes.




A command line argument parser for .Net with argument parsing rules based on PowerShell.


Common dialog classes for Windows Forms and WPF.

FormatC syntax highlighting

A class library that allows you to apply syntax highlighting to source code in a variety of languages.

D'ni number conversion

A web-based tool for converting to and from the D'ni number system used in the Myst series of games.