Who wrote 2.6.33 reminds us how much the open source world (and in particular the linux kernel community) excels in this area. For the single 2.6.33 release that was developed in about 3 months :

“As of this writing, 10,500 non-merge commits have found their way into 2.6.33 – fairly normal by recent standards. These changes added almost 900,000 lines while deleting almost 520,000 others; as a result, the kernel grew by a mere 380,000 lines this time around.”

So, if you happen to struggle to scale your team past the 10-people mark using your usual development habits, then there are maybe a few things you could learn from the open source world.

My personal understanding of why it works so well :

• good elite developers
• top-notch, distributed, super-fast and merge-friendly version control tools (e.g. git)
• Fault-proof and compromise-free (though sometimes not politically-correct) ways of enforcing software quality and architecture. Examples showing the disagreement-proof nature of the kernel development process include last summer’s Alan Cox vs Linus Torvalds dispute regarding the tty subsystem, or Linus Torvalds vs Hans Reiser argument regarding Reiser4’s plugin system that does not fit well into linux architecture
• result-oriented and meritocracy-driven way of managing the project
• decentralized development (made possible thanks to distributed SCM tools). To quote Linus Torvalds : “Centralized _works_. It’s just *inferior*.“
• modular architecture supporting the collaboration of many developers.  “The large number of developers and the fact that they are volunteers has an impact on how the system should be architected. With such a large number of geographically dispersed developers, a tightly coupled system would be quite difficult to develop — developers would be constantly treading on each others code.“

You might disagree on the reasons why it works so well (after all, that’s just my analysis based on my understanding of the situation), but the success is a reality, a fact.

Also, if you are tempted to think that it could not work in the corporate world, please think about that twice by taking another look at who wrote 2.6.33, where contributing companies are listed.

So… come on with your metrics, guys! they’re probably never going to match the “WTF/min” metric of a human-being senior developer.