If you pick as JVM language as suggested, why would you need to throw out any code?
When I worked at ITA Software which writes much of their stuff in Lisp (not the web stuff though), there was often worry that it meant new programmers would have to learn the language and so wouldn't be productive at first. But learning the code base takes a lot longer than learning the language, at least enough of the language to get significant stuff done.
If you have 10 years worth of legacy code written by 12,000 employees, I assume you're in the same boat.
When I worked at ITA Software which writes much of their stuff in Lisp (not the web stuff though), there was often worry that it meant new programmers would have to learn the language and so wouldn't be productive at first. But learning the code base takes a lot longer than learning the language, at least enough of the language to get significant stuff done.
If you have 10 years worth of legacy code written by 12,000 employees, I assume you're in the same boat.