PennyLane is 5 years old!

On 12 November 2018, PennyLane had its first moment in the spotlight when it was presented in the paper PennyLane: Automatic differentiation of hybrid quantum-classical computations, as a Python package that seamlessly integrates variational quantum circuit methods as part of hybrid computations. Five years later, the capabilities, features, and the community surrounding PennyLane have all grown and thoroughly changed the way we think of quantum programming.

To take you on a stroll down MemoryLane with us, we've prepared interesting insights from 5 years of dedicated development and research, as well as some marvellous treats to keep your PennyLane game strong for the next five. 😎

Contents

• The first five years of PennyLane
• How PennyLane began
• PennyLane on Discord and new Gatemojis!
• How to support PennyLane

The first five years of PennyLane

After its humble beginnings in late 2018, and a total of just five original contributors to its code, PennyLane rocketed through 2019, with hundreds of stars on GitHub, many new contributors, and more than 15 demos and tutorials, marking its first birthday by hosting the first QHack as a hackathon devoted to all things QML.

The steady trajectory of improvement included ten plugins before the end of 2020, plenty of application demos, as well as the advent of PennyLane-Lightning, a fast state-vector simulator written in C++.

By early 2021, more than 50 research papers had already been published based on PennyLane projects, the PennyLane Team had developed lots of new educational materials, and QHack 2021 grew to a beloved remote-friendly quantum hackathon with impressive prizes. And things were just starting to heat up!

In 2021 PennyLane contributors worked together to add features such as its Fourier module, kernel methods, and differentiable Hartree–Fock functionality, and the paper on Differentiable quantum computational chemistry with PennyLane rounded off the third year of PennyLane. With more than 1000 stars on GitHub, more than 50 demos, and the new PennyLane Codebook (formerly the Xanadu Quantum Codebook) that uses PennyLane to teach quantum, PennyLane had become a powerhouse.

Our highlights of 2022 include reaching a total of more than 100 code contributors on GitHub, several hundred research papers based on PennyLane projects, thousands of competitors at QHack 2022 and our other coding events, and countless new improvements to PennyLane. This was the year of new, fast simulator devices, Lightning-GPU and Lightning-Kokkos, as well as PennyLane's quantum information module, and the paper on Quantum computing with differentiable quantum transforms.

By its fifth year, PennyLane had truly become a powerful, unique, staple library of the quantum ecosystem, with a phenomenal community, exceptional contributors and researchers, and a sparkling bright future.

Having reached v0.33 in October 2023, PennyLane now also features pulse programming (see our paper) and Fermionic operator capabilities, with almost 2000 stars on GitHub and more than 150 code contributors.

To make PennyLane coding better, faster, and more effective, we launched some amazing new projects in 2023, including Catalyst and PennyLane Datasets, as well as the PennyLane Challenges platform to help you put your quantum programming prowess to the test! PennyLane is now taught in more than 75 university courses around the world, its performance is stunning, and it's as easy to pick up as checking out one of the more than 100 PennyLane Demos!

We continued helping our quantum ecosystem grow by hosting QHack 2023, the largest quantum hackathon around, by organizing the PennyLane Research Retreat to get feedback from top-notch researchers, and by kickstarting the Canadian Quantum Cup hosted by Xanadu.

How PennyLane began

To find out about the early days of PennyLane and its first five years in the quantum community, our PennyLane YouTube channel host Isaac De Vlugt sat down between two kets with some of the legends of PennyLane — Nathan Killoran, Maria Schuld, and Josh Izaac. A round of PennyLane-style drawing challenge was definitely in the books, too. 😉

PennyLane on Discord and new Gatemojis!

You didn't think we could have a birthday celebration without thinking of you, did you? 😺 We just saved the best for last.

You might have already seen us there, but PennyLane is now on Discord! Drop in and say hello, meet PennyLane coders from around the world, discuss all things quantum, and tell us about the amazing things you've done with PennyLane. 🤩

And in our colorful tradition, we have also created the thing your everyday life was missing outside of the coding screen — PennyLane Gatemojis!

To download, remix, and use them outside of our Discord server, stop by the PennyLane Gatemojis GitHub repository and build epic PennyLane circuits to your heart's content! 💕

How to support PennyLane

Thank you for spending five years of quantum with PennyLane! We hope you're ready for all the amazing things that are still to come and as excited as we are to keep pushing quantum programming to new heights. ✨

To find out more about the newest PennyLane features, visit our latest PennyLane v0.33 release and keep an eye on the PennyLane Blog and PennyLane Demos to learn about new applications and developments. You can also follow us on Twitter/X, LinkedIn, and Youtube, or join us on our Discussion Forum, the PennyLane Discord server, or the Xanadu Slack workspace.

And if you'd like to help make PennyLane's upcoming years as exciting as these first five, you can visit our repository on GitHub to learn more about how to contribute — and add us a star while you're at it. 😉