这个问题的精确措辞有点误导人:它不是“JVM”或“编译器”，因为有多个JVM供应商(jrockit是一个，IBM是另一个)和多个编译器。

The Sun JVM is written in C, although this need not be the case - the JVM as it runs on your machine is a platform-dependent executable and hence could have been originally written in any language. For example, the original IBM JVM was written in Smalltalk The Java libraries (java.lang, java.util etc, often referred to as the Java API) are themselves written in Java, although methods marked as native will have been written in C or C++. I believe that the Java compiler provided by Sun is also written in Java. (Although again, there are multiple compilers out there)

来自Java文档

编译器是用Java编写的，运行时是用ANSI C编写的

原则上几乎任何事情，通常C

实际上，Oracle JVM是用c++编写的，而不是C。

看看HotSpot JVM代码:http://openjdk.java.net/groups/hotspot/

Jikes RVM，一个广泛用于研究目的的自托管JVM，是用Java编写的。它不是人们在桌面上运行的那种，但它在我的“现在让我们展示一下这种语言的强大功能”列表中名列前茅。

一如既往的流行语言，用- C、c++编写。