9 Key Lessons from 25 Years of Linux Kernel Development

1. Short release cycles matter

In the early Linux project, major releases took years, causing long waits for users and large code integrations; shorter cycles allow new code to be merged quickly into stable bases, reducing pressure and enabling developers to catch the next cycle if they miss one.

2. Scaling requires a distributed, layered development model

Initially all changes went to Linus Torvalds, but this proved impractical; the kernel was split into subsystems (network, wireless, drivers, filesystems, etc.) each maintained by experts, expanding to hundreds of maintainers who review and integrate code without sacrificing quality.

3. The importance of tools

The community’s ability to grow relied on tools like BitKeeper and later Git, which transformed collaboration and made the massive kernel project manageable.

4. Strong community‑driven governance

When a respected developer rejects a patch, it is not merged, ensuring stability across diverse hardware from tiny devices to supercomputers.

5. Rigorous “no regression” policy

For over a decade the kernel promised that if it runs on a given platform today, future versions will also run there; regressions are quickly fixed, giving users confidence in upgrades.

6. Company involvement without domination

Since the 3.18 release, about 5,000 developers from ~500 companies contribute, working for their employers yet no single company can control the kernel’s direction.

7. No internal boundaries

Developers focus on their area but may modify any part of the kernel when justified, preventing problems from being hidden and encouraging holistic improvement.

8. Incremental feature growth

The kernel grew from 10,000 lines in version 0.01 to adding over 10,000 lines every two days, with small features eventually becoming major subsystems.

9. Collaboration yields a massive public resource

Since 2005, over 14,000 individuals from more than 1,300 companies have contributed, turning the kernel into a large, competitive yet shared codebase.

Source: http://www.techug.com/post/9-lessons-from-25-years-of-linux-kernel-development.html