December 23, 2021 by Olivier Goffart and Simon Hausmann

2021 in review

The year 2021 was fruitful yet busy for us at SixtyFPS.

Firstly, we'd like to thank our users, contributors, and customers. We've had many lovely interactions in issues that you filed, discussions that you started, and wonderful patches that you've contributed. We appreciate all the honest feedback, criticism, and words of encouragement. In this blog post we'd like to go through our highlights of 2021 🚀.


Throughout this year we began developing and establishing the business behind SixtyFPS. We want to become a reliable entity that enables other companies to develop commercial devices and applications. We also want to be the back-bone that supports and funds the development of our Open Source project.

  • In August we registered the limited liability company "SixtyFPS GmbH" in Germany, to offer worldwide commercial licenses and support.
  • In Fall we launched the Ambassador Program to offer a free license for small businesses to develop commercial apps, in exchange for helping us spread the word.
  • We launched a paid-for, perpetual license. Start for free, pay when you ship.
  • We've partnered with tQCS to provide additional services and solutions, especially in the Asia-Pacific region.
  • We're very grateful to have signed our first commercial customer. Keep an eye out for more details.
  • We're growing and hired @hunger to join us in January. He has many years of experience with tooling around GUI libraries and will expand this area for us going forward. He will also engage with our community. Feel free to say hi! 👋


Screenshot of Printer Demo
Screenshot of the printer demo

It's important to us that the community around the project is healthy, where we openly share ideas and experiences, welcome contributions, and we all learn from each other to constantly improve the technology.

We received many high-quality bug reports as well as patches that implement missing functionality or fix bugs. Shoutout to some of you ❤️:

As we started receiving contributions to the code base, @Be-ing opened a discussion about guaranteeing the FLOSS licensing of contributions through the CLA. After some back and forth we reached consensus on the wording, which turned into the most liked post on SixtyFPS on Reddit yet! The CLA has now been updated accordingly.

To help you get started using SixtyFPS, we recorded a video tutorial on the memory example on YouTube and published template projects for C++ and Rust.

We're happy to see the growth of our community also reflected in an increasing number of ⭐️ GitHub stars, going from 1000 to more than 2000 in just a few months.

In November we started a discussion on a new name for our product. Yes, we do realize SixtyFPS is not that good a name in times where monitors routinely display more than that :-). Thank you for all the great suggestions. Our new name will be announced in the beginning of next year, and we're working with a designer on a new logo.

Social Media & Forums

We started our journey into social media in 2021 with an interview with our friends at KDAB, and in July we joined Twitter as @sixtyfpsui. Thanks to everyone following our musings there :-).

In the spirit of transparency we began writing up regular weekly development reports, which can also be found in the Rust Reddit community, the Rust forums, and even in the famous This Week in Rust newsletter.

The IDE integration in action


Cargo UI 0.2 screenshot
Cargo-UI main screen

The entire code base made several leaps forward in terms of features and quality. We made eight releases in 2021, with two of them being particularly significant:

  • The 0.0.6 release introduced our awesome IDE integration with live-preview, semantic syntax highlighting, completion and a VS Code extension.
  • The 0.1 released marked the beginning of a series of releases that maintain compatibility. This is when we felt that we graduated from "lab mode" to "development mode", and we've since had several backwards compatible releases with new features and bug fixes.

In July we decided to build a real-world application to showcase SixtyFPS: Cargo-ui; it has become a really useful tool to manage dependencies, feature flags, as well as to trigger builds and tests.

Another show-case that we developed was enabling sixtyfps-viewer to be a front-end for shell scripts.

On the technical side the year is ending with our venture into running on microcontrollers and further improving our compiler with a new intermediate representation.

What's next?

Picture of the early printer demo running on the Raspberry pi Pico
Work in progress to get running on a Raspberry Pi Pico MCU

Now we're taking a few days off to relax, take a breath, and recharge our batteries. We'll be back in January and hope to share lots of good news with you, like our new name and logo. We looking forward to working together via the project. Hopefully we can also meet some of you in person at Embedded World in June. See you in 2022! 🎄🚀


Slint is a declarative GUI toolkit to build native user interfaces for desktop and embedded applications written in Rust, C++, JavaScript, and Python. Find more information at or check out the source code at