We’ve all heard of “open source." But have you heard of the software development concept called “inner source"?
It's a practice that tech company Amadeus has been emphasizing since last summer.
Inner source means adapting open source practices -- like collaboration and transparency -- to internal projects.
It is not about opening source code to outsiders. Instead, it's a form of intra-organizational open innovation that enables more colleagues to scrutinize code in a shared cloud repository. The goal is to get new ideas into production faster.
An Amadeus team could build on middleware source code built by other Amadeus engineers if they believed that changes were needed for an application they're developing.
As an example, a developer working on departure control systems could contribute a good idea into the code that belongs to another team, as long as the team responsible for maintaining those libraries agreed that the contributions made sense and were of high quality.
Breaking down silos
To learn more, Tnooz spoke with Christophe Defayet, who last autumn became director of research and development for airline IT at Amadeus.
Defayet said inner source work represents about one thousand to two thousand pull requests a month at Amadeus, up from nearly zero a year ago, for the company's sprawling R&D operations.
He claimed that "Amadeus is a pioneer in using this approach in the travel industry", noting that only a handful of airlines are also applying the philosophy to their code development. (That said, the inner source approach has already become widespread in other tech sectors and is used by companies like Facebook and Netflix.)
Defayet said:

"We're coming from a world where the code was owned by a single team and only this team was able to develop and evolve the product, to a world now where everybody can have good ideas and contribute to software development."
He expects that more and more IT projects at Amadeus will adopt an inner source approach on a case-by-case manner.

"Using inner source is really a way for us to be much more innovative and to reduce time-to-market for our products."
NB: Photo of Defayet with colleagues, courtesy of Amadeus.