[abiox]

> If Mark detected developer sentiment shifting, he can move just as fast as he wants to stanch the bleeding.

how is react's popularity at all material to facebook's interests? at best it means you get more outside contributions, but you already have plenty of talent internally.

[djur]

Having popular, high-profile open source projects helps Facebook attract more and better talent in three primary ways:

First, it increases the likelihood that the average programmer already is familiar with the tools they'd use at Facebook. It's useful for them to be able to hire people who already know React, Reason, etc. On occasion, they'll manage to find highly talented developers who either contribute to their projects or build useful related projects, and then they can make those people an offer. Even better, sometimes that's an entire startup they can acquihire.

Second, it increases the prestige of a job at Facebook. Most of the core public functionality of Facebook isn't particularly interesting to me, for example, but the stuff they're doing with OCaml is. The chance of me working there is still essentially nil but it's definitely less nil than it would be if I didn't know about projects like that.

Third, it gives them something really valuable to offer skilled devs -- the ability to become widely known and respected for your contributions to a popular open source project. That's worth a great deal to some people.

[cookiecaper]

Software companies are all about lock-in, controlling the platform, making sure they have control of as much user and dev attention as possible. At Facebook's world-eater size, the better question is "Why should we not seek to dominate this element of the development platform?"

I can't pretend to know the exact rationale behind Facebook's decision to open-source React, but there are several things to gain from controlling a major piece of the web infrastructure: influence/clout with browser vendors (decisions that may negatively impact React's performance now threaten a huge percentage of the web, not just Facebook.com), the ability to introduce more and more Facebook-controlled technology with something like React as a shoehorn ("You liked React, try Flow..."), PR benefit/good vibes, and so forth.

Platform control is the real showdown among big software companies. It makes your company downright inextricable. Just ask Microsoft.