Mustard
What Mustard is
Mustard is a free, open-source marketplace platform for the web, with tools for classified listings, auctions and purchases. Users can create accounts and adverts, add photos and videos, and use PayPal or Stripe for payments. Email notifications and messaging support communication between participants; feedback, a helpdesk and dispute resolution are also included. The platform provides API access and documentation, and includes payment processing. Hamjoint CIC develops and maintains Mustard for Hamjoint, a marketplace focused on amateur radio and electronics. Its listed plan is free. Mustard uses the GPL3 licence, which permits commercial use but requires derivative works to use the same licence. It is built on Laravel, which is licensed under MIT. The available platform is web.
Who it suits
Mustard may suit people setting up a web marketplace with listings, auctions and purchasing, including communities focused on amateur radio and electronics. Its GPL3 terms are relevant to anyone planning to modify or distribute derivative works.
What it does well
- Supports classified adverts, auctions and purchases.
- Accepts PayPal and Stripe payments.
- Includes messaging, email notifications and feedback.
- Offers API access and full documentation.
What to know first
- Available on web only.
- Derivative works must use the GPL3 licence.
Limits
The listed Mustard plan costs nothing and is licensed under GPL3. Derivative works must use the same licence.
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Mustard | GPL3 licence · commercial use allowed · derivative works must use the same licence | Free |
As withmustard.org lists them, read 8 Oct 2026. The maker's own page has the final word.
Getting started
- Visit https://withmustard.org/.
- Review the site's full documentation.
- Check the Mustard plan, listed as free.
- Use the web platform for marketplace listings, auctions and purchasing.
Verdict
Mustard brings core marketplace functions together, including listings, auctions, payments and dispute resolution. Its free listed plan and GPL3 terms are clear, but derivative works must retain that licence.
Questions
How much does Mustard cost?
The listed Mustard plan costs nothing.
Is Mustard open source?
Yes. Mustard is licensed under GPL3. Commercial use is allowed, and derivative works must use the same licence.
Which platforms support Mustard?
Mustard is available on the web.
Which payment integrations does Mustard list?
PayPal and Stripe are the listed payment integrations. Payment processing is also supported.
Who develops and maintains Mustard?
Hamjoint CIC develops and maintains Mustard for Hamjoint, a marketplace dedicated to amateur radio and electronics.
Does Mustard provide API access and documentation?
Yes. API access and full documentation are listed features.
Facts from Mustard's own pages
- Accounts and listings
- Features include user accounts and classified adverts. · withmustard.org, 8 Oct 2026
- Auctions and purchasing
- The platform includes auctions and a purchasing system. · withmustard.org, 8 Oct 2026
- Communication
- Mustard includes email notifications and messaging. · withmustard.org, 8 Oct 2026
- Documentation
- The site lists full documentation as a feature. · withmustard.org, 8 Oct 2026
- Framework
- Mustard is built on the Laravel framework, which the site says is licensed under MIT. · withmustard.org, 8 Oct 2026
- Help and disputes
- The listed features include helpdesk and dispute resolution. · withmustard.org, 8 Oct 2026
- Licence
- Mustard is licensed under GPL3, which allows commercial use but requires derivative works to use the same licence. · withmustard.org, 8 Oct 2026
- Maintainer
- Hamjoint CIC develops and maintains Mustard for Hamjoint, a marketplace dedicated to amateur radio and electronics. · withmustard.org, 8 Oct 2026
- Media and feedback
- The platform supports photo and video uploads and user feedback. · withmustard.org, 8 Oct 2026
- Payments
- The listed payment integrations are PayPal and Stripe. · withmustard.org, 8 Oct 2026
- Product
- Mustard is an open source auction and marketplace platform similar to eBay. · withmustard.org, 8 Oct 2026
Where Mustard stands on Freedom251
- Auction Software#9 of 32