Not quite, and this has had security implications. These are known as "full abstraction" failures, where JVM bytecodes can violate guarantees made by a language

Not quite, and this has had security implications. These are known as "full abstraction" failures, where JVM bytecodes can violate guarantees made by a language running on top of the JVM. The Joe-E language is basically a security-oriented subset of Java, and they had to explicitly decompile JVM bytecode of any code they're using, then recompile it in order to preserve full abstraction and avoid introducing vulnerabilities. C# is close to CIL bytecode as well, but they too had some full abstraction failures: http://lambda-the-ultimate.org/node/1588 http://lambda-the-ultimate.org/node/1588