co5e stands for "Codesys Opensource DEvelopment" with the D as a "5". We are free-spirited, passionate and clever developers. CODESYS has captured our ❤️ during our dayjobs, so developing using CODESYS came naturally. Thus co5e was born.

Fun fact: code 5 is a police code. Code 5 means "Stakeout" – Uniformed Officers Stay Away. It alludes to our past in which we used aliases to develop software anonymously, similar as the police in civilian clothing doing a stakeout anonymously.
It also refers to the idea that we like to be free and unencumbered e.g. no uniform.

If you share our passion for CODESYS, you are heartily welcome to join us.


Our mission is to have fun programing and learn along the way 👍
Our aim is to

  • learn
  • educate
  • innovative
  • write software which is easy to read
  • easy to extend
  • well documented
  • stimulate ease of use
  • stimulate open-source programming
  • stimulate development of well-designed software
  • developed by individuals, not as a company
  • non profit motive
  • MIT licensed

There are no caveats as any and all intellectual contributions (like code or ideas) will be MIT licensed by default with no exceptions. Many developers already publish under an MIT, GNU or Unlicensed copyright licenses anyway.

Our solutions

co⚡e: Sparkplug™ MQTT edge and host

An exciting Industrial IoT "killer app".
Easy in use as limited programming knowledge is needed since the library does the heavy lifting.
This library builds upon our unittest and linked list solution.
#co⚡e: Sparkplug™ MQTT edge and host

co♻e: A unittest framework for CODESYS

A free and open unit testing framework for any codesys based hardware
Easy in use and specifically designed for PLC State dependent unit testing.
Suited for 'Test Driven Development', scenario testing, xUnit syntax and test-report compatible.
#co♻e: A unittest framework for CODESYS

co🔗e: A Linked List Solution

A free and open object oriented Linked lists solution.
Linked Lists are especially suitable to implement simple, modular and powerful code with ease.
#co🔗e: A Linked List Solution


Any contribution to our projects are heartily welcomed

No matter your background, whether you are a beginner or an expert or just interested, anybody is welcome to contribute or even join us if you wish. You are important and not a number. Joining us is a good stepping stone to upgrade your personal skills. We share our exhaustive programming knowledge and experience with you. Off-course we listen and to learn from you to. If you wish to contribute in some form or another, there are various ways you can do this. e.g. via a project membership or on a 'per ticket' / 'pull-request' basis. Just drop us a line and we are happy to include you.


Our valuable contributors who have given us their time and effort;

Project Members:

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Valuable Resources

Since we develop as individuals we have regular jobs, we understand that good software development takes time and effort. However, this experimental and open form of development stimulates our creativity in full freedom without any pressure, boundaries or limitations! Creativity, fun and adding value to society are part of our DNA. This means that we do not have any hard deadlines to meet apart from those we impose on ourselves! Of course we set milestones and progress is being made. Please respect our efforts and our limited time.