What programming language for Googlebot written by? (Good programming languages for Web Cralwer)

Hello everyone!

Does anyone know what programming language for Googlebot written by?
Or I'd like to know what programming language is good for making Web crawler.

I found some open source crawler, like Nutch, Lucene (Probably this is indexer), and etc...
They are written by Java.

Is the Java good for making Web crawler?
How about C / C++? Is it also good for making?

Thanks for reading my question!
Your answer can be very helpful for me! Thank you!