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The Zephyr Project community unites upstream code developers and product development engineers in an open, collaborative environment to produce an RTOS that solves real-world problems. Check out these resources and engage with us through our events, Slack, mailing lists and more.


July 16, 2024

Pushing the Boundaries: Zephyr’s Role in Revolutionizing MCUs

July 11, 2024

User mode explained in simple words

July 10, 2024

Recap of the Zephyr Project meetup (May 23, 2024) in Karlsruhe, Germany

July 9, 2024

Expert Insights into Test-Driven Development, Pytest Integration, Emulators, and Unit Testing

Press Releases

June 27, 2024

How Open Source is Driving Technical Transformation of Vertical Industries

March 21, 2024

Zephyr @ Embedded World 2024

February 26, 2024

Renesas, STMicroelectronics and Ac6 join the Zephyr Project as it Launches the 3.6 Release

February 23, 2024

Welcome, Zephyr 3.6!



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Mailing Lists

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Community Guidelines

Read Before Contributing

IMPORTANT: Before you contribute, look through the mailing list archives, bug lists, and documentation first, to see if your question has already been answered. You will get a better response from people if you have already done your due diligence to find obvious or partial answers.

  • Be nice: Be courteous and polite to fellow members of the list.
  • Respect other people: No regional, racial, gender or other abuse will be tolerated.
  • Keep it clean: Keep the language clean (no swearing)
  • Be helpful: Be patient with new people and be willing to jump in to answer questions.
  • Stay calm: The written word is always subject to interpretation, so give people the benefit of the doubt, and try not to let emotions get out of control.
  • Keep it legal: Make sure that you have the legal right to post your content and are not violating copyright or other laws.

Code of Conduct

In the interest of fostering an open and welcoming environment, we pledge to make participation in our project and our community a harassment-free experience for everyone.  As such, we’ve included a Contributor Covenant Code of Conduct in our Zephyr Project GitHub repository.

Keep it short

Remember that thousands of copies of your message will exist in mailboxes:

  • Keep your messages as short as possible.
  • Avoid including log output (select only the most relevant lines, or place the log on a website or in a pastebin instead)
  • Don’t excessively quote previous messages in the thread (trim the quoted text down to the most recent/relevant messages only).

Use proper posting style

  • No HTML or Rich Text: Set your mailer to send only plain text messages to avoid getting caught in our spam filters.
  • Do not top post: Top posting is replying to a message on “top” of the quoted text of the previous correspondence. This is unwanted in mailing lists because it increases the size of the daily digests and is confusing and incoherent. By default, most email clients top post. Please, remove the irrelevant part of the previous communication (in case of more than a single correspondence) and use bottom, interleaved posting
  • Using interleaved posting: Bottom, interleaved posting is replying to the relevant parts of the previous correspondence just below the block(s) of sentences. For a comment to another block of sentences of the same quoted text, you should move below that relevant block again. Do not reply below the whole of the quoted text. Remove any irrelevant text.
  • Use links: Please provide summaries and URLs to articles wherever possible. Avoid cutting and pasting whole articles especially considering all may not be interested.
  • Don’t include attached files: Upload your file to this wiki or another website and post a link to the file from your email message.

Do not hijack threads

Post new questions or new topics as new threads (new email message). Please do not reply to a random thread with a new question or start an unrelated topic of conversation in an existing thread. This creates confusion and makes it much less likely that you will get a response.

Do not cross post

Avoid posting to multiple lists simultaneously. Pick a mailing list that is most suitable for your post and just use that. CC’ing multiple lists should be avoided.

Subscribers only

Only subscribers can post to our mailing lists. If you would like to contribute to our mailing lists, we think it is only fair that you be a subscriber. Please note that if you want to participate only occasionally, you can subscribe to a list and set your email options to digest or no mail and read the web archives when you want to catch up.

Additional Resources

Mailing list guidelines by Shakthi Kannan (PDF): Great guideline summary and examples of posting styles.

We like communications to run smoothly. To that end, here are some guidelines for participating in our bug tracking system.

  • Be patient with others: Sometimes people post imperfect bug reports. In case of missing information, kindly tell reporters how to provide it, and/or suggest what they can do to improve the bug report.
  • Stay on topic: Don’t start endless debates on topics not directly related to the scope of a specific bug report.
  • Use proper quoting practices: Avoid quoting complete previous comments by stripping unneeded lines, and avoid answering above the quoted text.
  • Don’t abuse your privileges: Submitters have permission to edit their bugs. If you abuse this privilege – for example, by reopening a bug that the maintainers have closed – your privileges will be revoked.

What to do if you find a bug

  • Search first: Try to avoid filing duplicates by searching to see whether your issue has already been filed.
  • Ask: You can ask on our mailing lists to see if anyone has seen this issue before to gather more details or see if someone has a workaround.
  • Submit a bug report: Give us as many details as possible about what happened and how your issue can be reproduced.
  • Track our progress: Get feedback from the development community and track resolution status.
  • Provide a fix: If you know of a fix and/or workaround, please let us know.

Export Compliance

By downloading Zephyr, upstream source used to generate features or components, or any binaries generated by the Zephyr Project, you acknowledge that you understand all of the following:

The Zephyr Project, its component parts and technical information may be subject to the U.S. Export Administration Regulations (the “EAR”) and other U.S. and foreign laws and may not be exported, re-exported or transferred

(a) to any country listed in Country Group E:1 in Supplement No. 1 to part 740 of the EAR (currently, Iran, North Korea, Sudan & Syria);

(b) to any prohibited destination or to any end user who has been prohibited from participating in U.S. export transactions by any federal agency of the U.S. government; or

(c) for use in connection with the design, development or production of nuclear, chemical or biological weapons, or rocket systems, space launch vehicles, or sounding rockets, or unmanned air vehicle systems.

You may not download the Zephyr Project, its component parts and technical information if you are located in one of these countries or otherwise subject to these restrictions. You may not provide the Zephyr Project, its component parts and technical information to individuals or entities located in one of these countries or otherwise subject to these restrictions. You are also responsible for compliance with foreign law requirements applicable to the import, export and use of The Zephyr Project, its component parts and technical information.

The Zephyr Project is covered under a TSU exception. Its ECCN is 5D002TSU.