November 28, 2016

tl; dr;

InnerSourcing is adopting opensource principles in the enterprise: community, transparency, collaboration. It requires a shift in company culture and processes to gain benefits of InnerSource: increased software reuse, improved quality, open innovation, accelerated development, improved mobility.

Platform and commonly used products (libraries, modules, documentation etc.) can gain most benefit of InnerSource.

Its usage can be fostered by introducing pilot products. I suggest to start from documentation, as it is easy to contribute to and does not result in risk of losing quality.

However, the shift of the culture is also needed (both development and management) to support these principles, as well as focus on products more instead of teams. Community leader(s) and evangelist(s) are needed to help this change to happen.


Open source is not just about licensing or free price, it’s also about workflows, how to develop software collaboratively. Sytse Sijbrandij @ GitLab states OpenSource practices for enterprise:

  1. Visibility: all software projects are by default visible to all employees.
  2. Forking: everyone who can see the code, can create a copy (fork) where they can make changes freely; these forks are visible for everyone.
  3. Pull/merge requests: even people outside the project are able to suggest changes and you can have a conversation about the code with line comments.
  4. Testing: software includes unit- and integration-tests so that changes can be made with less fear of causing problems.
  5. Continuous Integration: every proposed change is automatically tested and the result is shown with the change.
  6. Documentation: all software projects include a readme that describes what the software does, why that is important, how run it and how to develop it.
  7. Issue tracker: there is a public issue tracker in which everyone can submit a bug or ask a question.

While for oldskool companies this might seem weird, I think that any company valuing Agile principles more or less is familiar with them.

The most wonderful thing about open source is that these principles can be used not only in developing software, but also writing documentation (Azure articles,, RaspberryPi), commonly creating websites. People even collaboratively write books, develop hardware and even cars.

However even in open communities adopting open source principles in not always a common sense.

What’s that InnerSource

Originally stated by Tim O’reilly back in 2000 - it’s basically adopting open source principles in the enterprise.

“InnerSource takes the lessons learned from developing open source software and applies them to the way companies develop software internally.” - is written in PayPal’s InnerSource commons.

Bas Peters from GitHub had a great talk on InnerSourcing at HighLoadStrategy 2016 conference. Some of my takeaways from his talk:

How to innersource in the company

Although it is quite clear what InnerSourcing is, there is very little information how to start it in the company.

Klaas-Jan Stol and Brian Fitzgerald define nine factors that influence the adoption of InnerSource in the enterprise:

Innersource factors

Panna Pavangadkar of Bloomberg, Global Head of Engineering Development Experience states three pillars to making inner source successful:

My takeaways from these information sources:

What are the concerns of InnerSourcing

According to the recent interview, security is one of the biggest concerns within InnerSourcing.

The cultural shift, knowledge concentration and firewalls are also mentioned as challenges.

What is the right tool to leverage InnerSourcing

As InnerSource is about culture, collaboration of the developers community, it says nothing about the tools. Therefore we should focus on processes first, and then choose the most proper tool.

PayPal had a positive experience with GitHub, as described by Andy Oram in his book, but all this benefit can be achieved with other competitive tools, for example, GitLab or Atlassian product suite.

References 2af906c3e0ae#.8nmrntlcn