Seibel: As a Java guy at Google, do you think it could be used more? Leaving aside the force of history and historical choices, if somehow you could wave a magic wand and replace all of C++ with Java, could that work?
Bloch: Up to a point. Large parts of the system could be written that way, and over time, things are moving in that direction. But for the absolute core of the system - the inner loops of the index servers, for instance - very small gains in performance are worth an awful lot. When you have that many machines running the same piece of code, if you can make it even a few percent faster, then you've done something that has real benefits, financially and enviromentally. So there is some code that you want to write in assembly language, and what is C but glorified assembly language?
http://google-opensource.blogspot.ca/2009/01/opengse-release...
(I think Google Sites is also written in Java).
Amazon is pretty much a big Java shop (don't forget the companies they acquired as well). Check out their jobs site.
On top off edwinnathaniel's list, add Google Sites, Google Docs, and Mapreduce frameworks such as Flume Java.
Likewise with Amazon. My understanding, from chatting with some Amazon engineers at a conference, is that they have a pretty heterogeneous portfolio, even including some Perl and Oracle PL/SQL.
Others who are better informed, please correct.