It seems all companies including Google, Yahoo and facebook understand one thing well now. They need to keep the developer community close to them to be able to create standards and be in a position to control the industry.
In its attempt facebook has released a framework they call thrift in the open source and followed up with releasing a service for thrift called scribe.
Both are aimed at developers who want to use various technologies to aggregate and display data from multiple servers. While thrift allows developers to run programs written under various languages like c, php and java, scribe lets developers aggregate data from many servers and process them. Scribe is a service that runs inside thrift.
Keeping open source developers is a good strategy. Demonstrated by microsoft and sun for many years. This is why Google chrome sucked for most firefox users. This is why opera isnt tht widely adopted dispite being a terrific browser. They havent been able to woo the developer community.
Firefox on the other hand is a developers best pal. In turn developers have given the firefox users some amazing applications that make their lives easier and more productive. Even though chrome is faster than firefox in both rendering visited page from sites and executing javascript, firefox users have not stopped using firefox.
Why? because firefox is not a browser. Its a platform.
It lets them pick from thousands of free firefox extensions that do a great job of making their lives easier. Like the firefox web developer plugin or the elasticfox extension to manage amazon web services.