How can a JVM be written in Java

java jvm bootstrapping
kji picture kji · Feb 17, 2010 · Viewed 8.2k times · Source

I was briefly reading about Maxine which is an open source JVM implementation that written in Java. This sounds circular to me. If java requires a virtual machine to run in, how can the virtual machine itself be written in Java (won't the VM code require a VM in which to run, and so on?).

Edit: Ok, so I see I overlooked the fact that Java doesn't have to run in a VM. How then does one explain how a LISP compiler can be written in LISP? Or should this be a new question altogether?

Answer

Ignacio Vazquez-Abrams picture Ignacio Vazquez-Abrams · Feb 17, 2010

Your assumption that Java requires a virtual machine is incorrect to begin with. Check out the project GCJ: The GNU Compiler for the Java Programming Language.

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