The Chapel Programming Language

Accelerate Development with a Productive Language

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Productivity Highlights

Easy and Fast Ramp Up

Chapel enables users to bring new contributors up to speed in record time.

Writes Faster,
Runs Faster

Peer-reviewed studies show that Chapel is faster and more productive than alternatives.

Language Tooling Support

The Chapel language server and linter integrate with your favorite editor to supercharge your development experience.

Concise but Fast

Computer Language Benchmarks Game

When compared against other common programming languages, solutions built in Chapel are both compact and performant.
(swipe to zoom in on the fastest languages)

Blazing Fast Speed with Chapel

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Designed for Supercomputers, Delivers on Desktop Too

Sorting

Chapel's standard library sort runs an order of magnitude faster than that of the next fastest language.

Learn More

Poisson Solver

Chapel solutions to Poisson's equation outperform C++ solutions while requiring less code overall.

Learn More

1 Billion Row Challenge

Chapel can process massive amounts of data, all on a single multi-core machine.

Chapel and AI

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Doing AI in Chapel

As a general-purpose, scalable parallel programming language, Chapel is well-suited for computations in Artificial Intelligence and Machine Learning. In practice, Chapel can either be used as a scalable driver of existing, highly tuned library routines for AI/ML, or to write novel distributed algorithms that do not yet have a vendor-tuned library solution. Moreover, due to its portable design and implementation, Chapel avoids lock-in to any single hardware vendor.

Chapel Community Calendar

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Non-Google Calendar users: If your app supports subscribing to online calendars, click to copy this into it.

Chapel Community Meetings

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To view Chapel meeting details, see the community calendar

Chapel Community Resources

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The following are resources related to joining and growing the Chapel community:

Q&A / Discussions: Places to ask questions and interact with the Chapel community asynchronously
Community Meetings: Opportunities to meet with the Chapel community in real-time
Social Media: Keep up with the latest news and help amplify it
Calendar: Coordinates of upcoming meetings and events
Newsletters: Quarterly newsletters summarizing community highlights
ChapelCon: The Chapel event of the year
Governance: How the Chapel project is governed

Chapel Governance

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Chapel is an established project in the High Performance Software Foundation and by extension, the Linux Foundation.

Chapel is governed by a Technical Steering Committee (TSC) whose topics and meeting notes are tracked on GitHub.

Information about the TSC and Chapel’s governance can be found in its technical charter and GOVERNANCE.md documents on GitHub.

Chapel Social Media

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These are Chapel’s official social media channels, which are also linked in our website’s footer. Please follow us and repost!

If you’d like to highlight your work through our social media accounts, fill out this form to submit your request.

Chapel Subreddit

Reddit

Chapel YouTube

YouTube

Beyond the channels above, we always appreciate seeing Chapel-related content on other community forums such as Reddit, HackerNews, Lobste.rs, etc.

Chapel: Built for Parallelism

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Parallelism at Any Scale

Chapel is built from the ground up with productive and performant parallel computing in mind. Conventionally, leveraging parallelism at different scales requires different programming models with different features, syntax, and interfaces. Chapel programs can leverage multiple types of parallelism with a single unified set of language features:

Shared-Memory Parallelism

Effortlessly leverage your multi-core CPUs for task and data parallelism.

CPU and GPU Parallelism

Update a handful of lines of code and your application can be ready for GPU execution.

ChapelCon

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ChapelCon is the annual event for the Chapel community, featuring talks, tutorials, coding sessions, and office hours. ChapelCon is open to anyone interested in Chapel or parallel programming. In recent years, it has been held online and has been free to attend.

ChapelCon ‘25: October 7–10, online, in a virtual format
ChapelCon ‘24: June 5–7, online, in a virtual format

ChapelCon was originally known as CHIUW—the Chapel Implementers and Users Workshop—but was renamed in 2024.

Community Q&A / Discussion Forums

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The following are places to ask questions, file issues, and/or interact with the Chapel community:

Download and Install Chapel

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From Source

To download and install Chapel from source, download chapel-2.8.0.tar.gz from GitHub, then unpack and build it as described in the Quickstart instructions.

With Spack

To get started with the Chapel Spack package:

Install the Spack package manager on your system, if it isn’t already there.
To customize the Chapel installation, use the variants of the Chapel Spack package as opposed to the normal CHPL_* environment variables. Most settings described in Chapel’s documentation can be set using variants of the Chapel Spack package.
Install the Chapel package, specifying any variant desired. For example, to also install the chpldoc tool, use spack install chapel+chpldoc.

Examples

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Featured Examples

GPU Support [ Code ] 🔗
Engin Kayraklioglu,January 2025

A repository of GPU programming examples in Chapel

Other Examples

Optimization Algorithms [ Code ] 🔗
Tiago Carneiro,February 2021

Large-scale exact distributed optimization algorithms including prototype for enumerating all feasible and complete configurations of the N-Queens

Advent of Code 2023 [ Code ] 🔗
Michelle Strout,December 2023

A repository of Advent of Code 2023 programs written in Chapel

Monte Carlo Simulation [ Code ] 🔗
Engin Kayraklioglu,September 2024

Tutorial of Monte Carlo simulation written in Chapel

Get Involved

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Interested in helping the Chapel project grow?

Here are some ways to get involved and help nurture the Chapel community:

Easy Actions

Star the project on GitHub
Follow us on social media
Subscribe to our YouTube channel
Like, repost, and amplify Chapel content you appreciate
Attend weekly project and/or deep-dive meetings
Ask questions on Chapel discussion forums
Invite a Chapel community member to…
- speak at a seminar you’re involved with
- run a demonstration for your group
- take part in an interview on your blog/podcast
Propose some other way to get involved

Use Chapel

Download and install Chapel
Compile and run sample codes:
- from the examples/ directory of your installation
- from the website’s front page
- from the examples page and repo
Reach out to a Chapel developer to explore pair-programming code patterns of interest
Learn Chapel
Write your own applications in Chapel
Report any bugs you encounter or feature requests you wish for as GitHub issues
Share your work with the community by
- mentioning it on Discord
- doing a 5-minute demo in our weekly project meeting
- proposing a longer introduction in a weekly deep-dive meeting
- proposing and writing a Chapel blog post
- submitting a talk to ChapelCon
- contributing the code back as a Mason package, example, or test¹

Help Improve Chapel¹

Improve or extend Chapel’s documentation by editing its sources
Improve the Chapel website
Add, improve, or extend Chapel’s standard or package library modules
Check open Chapel issues for ones labeled good first issue or easy / straightforward
Browse Chapel’s documentation for contributors
Compare, analyze, and improve Chapel performance relative to other approaches
Conduct and publish original research relating to Chapel
Port Chapel to, support it on, or package it for a new platform
Help improve the Chapel compiler and/or runtime

Help Fund Chapel

Fund work you’d like to see done on, or in, Chapel through:
- development and/or support contracts
- the Linux Foundation

To contribute back to the Chapel GitHub repository, be sure to familiarize yourself with the Developer Certificate of Origin (DCO) ↩︎ ↩︎

GPU Programming Made Simple with Chapel

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GPUs are the powerhouse of modern computing systems. Chapel’s general-purpose capabilities for parallelism and locality control makes GPU programming as easy as programming a multi-core CPU. These capabilities makes GPU programming intuitive on a laptop with a GPU, on a leadership-class supercomputer, or anything in between. Chapel supports programming NVIDIA and AMD GPUs in a vendor-neutral way; the same code can be used on GPUs from both vendors without any change.

Learn Chapel

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Recommended Resources

Introductory Tutorial

Learn about the basics of Chapel, including how to compile and run Chapel programs. This tutorial works through a heat diffusion simulation.

Parallel Programming in Chapel

Learn about how Chapel can scale complex dynamics programs with Alex Razoumov’s 3 part course on parallel programming in Chapel.

Chapel Feature Primers

Learn more about specific features of the Chapel langauge with our primer series.

Mason Packages

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Only show packages that work with Chapel 2.0+

Papers

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Benchmarking and Language Comparisons

Heading Towards Energy Savings or Just Performance: Case-Study on Message Aggregation-Based Runtimes [ Slides ] 🔗
Shubhendra Pal Singhal, Aaron Welch, Nathan Wichmann, Akihiro Hayashi, Oscar Hernandez, Bradford L. Chamberlain, Steve Poole, and Vivek Sarkar, CUG 2026, April 28, 2026

This paper and talk look at the impact of using communication aggregation on energy as well as performance, showing benefits to both in Chapel

Comparing Distributed-Memory Programming Frameworks with Radix Sort [ Paper | Slides ] 🔗
Michael Ferguson, Ryan Friese, Shreyas Khandekar, Matt Drozt, PAW-ATM 2025, November 16, 2025

This paper and presentation compare implementations of radix sort in Chapel, MPI, SHMEM, and Lamellar in terms of productivity and performance

Papers Archive (Reverse Chronological)

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The following is a(n incomplete) reverse-chronological listing of Chapel publications and papers. Note that our archives include many talks that have not made it onto this new website yet, some of which can be found on the old website. If there is a specific paper you’re looking for that’s not listed here, please let us know.

2026

Efficient and scalable branch-and-bound algorithm for exact qubit allocation [ Paper ] 🔗
Jean-Philippe Valois, Guillaume Helbecque, Nouredine Melab, Future Generation Computer Systems, volume 179, June 2026

This paper uses a Chapel-based parallel branch-and-bound framework for exactly solving challenging qubit allocation instances. Experimental results show near-linear intra-node scaling and strong multi-node performance, and deliver new reference optimal solutions for benchmark circuits of up to 26 qubits, exceeding previously reported instances.

Presentation Archives (Reverse Chronological)

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The following is a(n incomplete) reverse-chronological listing of Chapel presentations. Note that our archives include many talks that have not made it onto this new website yet, some of which can be found on the old website). If there is a specific talk you’re looking for that’s not listed here, please let us know.

2026

30 Years of Scalable Parallel Programming: So Many Hardware Advances, So Few Broadly Adopted Languages [ Slides ] 🔗
Brad Chamberlain, PNW PLSE 2026, May 5, 2026

A reflection on how much HPC hardware has changed over the past 30 years, yet how little the languages we use to target them have

Presentations

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Featured Chapel Presentations with Video

Scalable Parallel Programming with Chapel: From Multicore CPUs to GPU-Powered Supercomputers (a.k.a What Chapel Users Get Done and How) [ Slides | Video ] 🔗
Engin Kayraklioglu, LUMI User Coffee Breaks, October 15, 2025

This talk focuses on user accomplishments with Chapel. It then covers some unique features of the language and how they ease scaling from laptop to supercomputer.

Writing Parallel Research Software in Chapel [ Slides | Video ] 🔗
Brad Chamberlain, HiRSE Summer of Programming Languages, September 3, 2025

This talk addresses the question 'Why use Chapel instead of other languages?', covering Chapel characteristics and resources in a bit more detail than most talks

Resources

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Highlights

Chapel: Accessible Parallel Programming from the Desktop to the Supercomputer [ Slides | Video ] 🔗
Brad Chamberlain, KAUST/KSL seminar, May 13, 2025

A gentle introduction to Chapel for a general scientific computing audience, covering motivation, apps, performance, and resources.

Vendor-Neutral GPU Programming in Chapel [ Slides | Video | Demos ] 🔗
Jade Abraham and Engin Kayrakloglu, HPE Developer Meetup, online, July 31, 2024

This is a talk with demos that introduces the use of Chapel to program GPUs in a vendor-neutral manner.

Scaling your Workflows with Chapel

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Workflows written using Chapel scale enormously. The same code written on your laptop can perform on however many nodes you can give it, be it one, dozens, or thousands. Applications written by Chapel users have successfully scaled to more than 8,000 compute nodes, 1,000,000 CPU cores, and 1,000 GPUs. The largest supercomputers in the world run Chapel. No matter the scale of your system, you can scale too.

Scaling Results with Chapel

Arkouda Argsort

Arkouda's argsort routine can sort 256 TiB of data in just 31 seconds, scaling to more than 8,000 nodes. All in ~100 lines of Chapel code.

Tutorials

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Tutorials

ChapelCon 2024 Chapel Tutorial [ Slides | Video ] 🔗
Jade Abraham, Michael Ferguson, Daniel Fedorin, ChapelCon 2024, June 5, 2024

75-minute recorded tutorial presented at ChapelCon 2024

October 2023 Chapel Tutorial [ Sample code from slides ] 🔗
Chapel Team, Virtual, October 16, 2023

Slides:

Full Day Chapel Tutorial presented in October 2023.

The Chapel Programming Language

Accelerate Development with a Productive Language

Productivity Highlights

Easy and Fast Ramp Up

Writes Faster, Runs Faster

Language Tooling Support

Concise but Fast

Computer Language Benchmarks Game

Blazing Fast Speed with Chapel

Designed for Supercomputers, Delivers on Desktop Too

Sorting

Poisson Solver

1 Billion Row Challenge

Chapel and AI

Doing AI in Chapel

Chapel Community Calendar

Chapel Community Meetings

Chapel project weekly meeting

Chapel deep-dives and demos

Technical Steering Committee (TSC) Meetings

Chapel Community Resources

Chapel Governance

Chapel Social Media

Chapel Social Media Accounts

Chapel Subreddit

Chapel YouTube

Chapel: Built for Parallelism

Parallelism at Any Scale

Shared-Memory Parallelism

CPU and GPU Parallelism

ChapelCon

Community Q&A / Discussion Forums

Stack Overflow

GitHub Issues

Discord

Slack

Discourse

Download and Install Chapel

From Source

With Spack

Examples

Featured Examples

Other Examples

Get Involved

Interested in helping the Chapel project grow?

Easy Actions

Use Chapel

Help Improve Chapel1

Help Fund Chapel

GPU Programming Made Simple with Chapel

Learn Chapel

Recommended Resources

Introductory Tutorial

Parallel Programming in Chapel

Chapel Feature Primers

Mason Packages

Papers

Benchmarking and Language Comparisons

Papers Archive (Reverse Chronological)

2026

Presentation Archives (Reverse Chronological)

2026

Presentations

Featured Chapel Presentations with Video

Resources

Highlights

Scaling your Workflows with Chapel

Scaling Results with Chapel

Arkouda Argsort

Tutorials

Tutorials

Writes Faster,
Runs Faster

Help Improve Chapel¹