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MuleSoft got its start years ago with a great open source project, Mule ESB.

Today we continue to be big believers of open development and that’s why every single line of the community edition source code is publicly available on Mule.

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We leverage many open source technologies everywhere within Anypoint Platform, from the core integration engine, Mule ESB; to hundreds of connectors, tooling, and plugins of all kinds.

Openness means nothing without community. At the same time, community is not made up of lines of code. Community is people. Vincent Hardy, Director of Engineering at Adobe Inc. has eloquently described in his article, “Why Do Developers Contribute to Open Source Projects?” what motivates people to contribute to open source projects, and more precisely, how collaboration benefits the contributors — worth checking out!

Growing with open source

Let me briefly describe my own personal experience with open source by emphasizing some of the points in Vincent’s article. After a long lasting relationship with communities for instance, founding linux local user groups or even contributing to big projects like the KDE software compilation, I found myself working in a professional project using Mule ESB.

My relationship with Mule could have ended there, just do the work with it and jump to the next thing. Yet, I found the integration problem so exciting that I decided to go further. This drove me to the MuleSoft forums, and the forums eventually led me to reporting bugs and improvement suggestions on the issue tracker.

I’m a developer, and we developers find joy in fixing thing — not just pointing out the problem. As a result, I started sending patches that fixed those problems to MuleSoft.

At that point, I had already grown within my company thanks to this attachment to the source. It didn’t stop there. My patches and forum posts gave me enough recognition to be invited to coauthor a book: Mule In Action, Second Edition. Writing this book made me develop a close relationship with MuleSoft, and eventually making a living out of being part of the community I love.

Many of my colleagues have a similar background; and I’m sure every open source contributor has an exciting story to tell. And I’m sure most of them share the Vincent’s view on the goodness of contributing to an open source project.

How to contribute to Mule

Let me invite you to become an open source contributor, and if you let me go even further, I’d like to invite you to be part of the Mule ESB open source community.

There are different ways to participate in this community, and each of them requires a different abilities, not necessarily just development skills. Let’s review:

Request an improvement or report a problem in the issue tracker

There’s no perfect piece of software in the world. If you find a problem or you have a suggestion to improve Mule ESB, sign into our issue tracking system, make sure the issue is not already reported, and then report the new issue.

If you are reporting a problem, it’s especially important to include, if possible, a mechanism to reproduce the error, either in the form of a minimal app to reproduce the problem or in the form of a comprehensive list.

If the problem cannot be reproduced easily, the odds that someone else in the community picks up that issue and submits a pull request to fix it are low.

Submit a Pull Request

If you are a developer who wants to contribute code, we’d be happy to receive your contribution and incorporate it to the mainstream repository.

Three very relevant but often forgotten steps of this guide are:

  • Sign the contributors agreement. A necessary step, common to all big open source project. Thankfully it is quick and painless.

  • Include the issue identifier in the commit description. This is very necessary as we need to keep record of the issue related with every single commit.

  • Cover your changes with tests. No contribution is completed if there are no tests covering its functionality.

If you need ideas around what bug to fix, or which new functionality to implement, just take a look at the issue tracker and find an unassigned issue. And remember, new functionality that breaks backwards compatibility should be merged against mule-4.x otherwise you can use mule-3.x.

Improve the documentation

If you find any area of improvement in the documentation there are two options:

  • The quick one is to use the Rate this page and leave feedback area at the top/bottom of every documentation page. Make sure you add some written feedback to your rating to make sure we understand exactly what can be improved.
  • Or to send your improvement request to

Help in forums on Stack Overflow

There are a number of Mule related tags: mule, mule-studio, mule-component, etc. in Stack Overflow, they’re relatively popular and get questions pretty often.

If you want to test your Mule skills you can visit those tags or our forum and try to help some other users in exchange of some stack overflow karma. This is a very relevant site which reputation system is becoming a very well considered knowledge measurement in hiring.

Help through social networks

Social networks, especially Twitter, post questions quite often. To find those questions keep an eye on hashtags like, #mulesoft and #muleesb along with mentions to @muledev and @MuleSoft.

You might also be interested in following @mulesoft and @learnmulesoft for the latest news and learning materials.

Share your knowledge in a meet up or in a blog post

If you understand Mule ESB, if you have learned how to leverage a certain connector or any other interesting matter — why not sharing your knowledge by hosting an event or writing a blog post?

Meetup is a very trendy site for organizing events. You might want to organize your own event or to propose one to any of the existing groups.

If you are going to speak around Mule ESB in an event or write a blog post, make sure you mention it to @muledev or @MuleSoft — you might get a retweet or more help.

Get rewarded for becoming a champion

At MuleSoft, we’re thankful for our vibrant community and all the contributions we’ve had along the years. As a gesture of recognition we have created the MuleSoft Champions Program!

With the MuleSoft Champions Program you get rewarded with cool prizes for expanding and sharing your knowledge:

  • USB powered mini-fridges
  • Your own flying drone
  • Conference tickets
  • MuleSoft swag

If you contribute to the MuleSoft community make sure you register in the Champions program for rewards!