Folkert
About
Folkert
- Systems software engineer
- folkert@tweedegolf.com
Folkert is an expert in systems programming and holds a master's in Computer science. He has made major contributions to the creation of the friendly, fast, functional language called Roc - in fact, he has so far written about half of the code; He co-teaches (and co-creates) the university course teach-rs; And he is working on Rust implementations of the Network Time Protocol, ntpd-rs and zlib.
Difficult problems don´t rattle him. In fact, we can rely on Folkert to face them head-on and produce solid implementations in remarkably little time.
In his spare time, Folkert often continues to work on languages (natural or other) and he likes to cook or spend time in the garden.
Blog posts
What is my fuzzer doing?
Fuzz testing is incredibly useful: it has caught many a bug during the development of NTP packet parsing and gzip/bzip2 (de)compression.
But I've always been unsatisfied with the fuzzer being a black box. When it runs for hours and reports no issues, what do we actually learn from that? In ntpd-rs we've previously had a bug fly under the radar because the fuzzer just did not reach a large chunk of code. So, does my fuzzer actually exercise the code paths that I think it should?
Translating bzip2 with c2rust
Over the past couple of months we've been hard at work on libbzip2-rs, a 100% Rust drop-in compatible implementation the bzip2 compression and decompression functionality.
For this project, we used c2rust for the initial translation from the C code to a Rust implementation. The generated Rust code has now been cleaned up and made safe where possible. This post describes our experiences using c2rust for this project.
Open-source work
openleadr-rs
openleadr-rs is a work-in-progress Rust implementation of the OpenADR 3.0 specification. OpenADR is a protocol for automatic demand-response in electricity grids, used, for example, for dynamic pricing or load shedding.
openleadr-rs was initiated by us as openadr-rs, but is now part of the OpenLEADR project, governed by the Linux Energy Foundation.
zlib-rs
zlib-rs is a memory-safe Rust implementation of zlib, the widely-used compression library, used primarily on the web to provide gzip compression to the text/html/js/css we send around.
The initial development of zlib-rs was started and partly funded by Prossimo. It's now governed by the Trifecta Tech Foundation as part of their Data Compression initiative.
ntpd-rs
ntpd-rs is an open-source implementation of the Network Time Protocol completely written in Rust, with a focus on exposing a minimal attack surface. This video explains how ntpd-rs brings NTP into the modern era.
The project was initially funded by ISRG's Prossimo, as part of their mission to achieve memory safety for the Internet's most critical infrastructure. The NTP initiative page on Prossimo's website tells the story.
ntpd-rs is part of Project Pendulum. In July of 2023 the Sovereign Tech Fund invested in Pendulum, securing development and maintenance in 2023, and maintenance and adoption work in 2024.
teach-rs
teach-rs, formerly Rust 101, is a collection of modular teaching materials to build a university course for computer science students, introducing the Rust Programming Language. It is open source and thus available to anyone who wants to teach Rust.
It is governed by the Trifecta Tech Foundation.
Read one of our teach-rs blogs for more info.
Roc
