douchuan/jvm

---

douchuan/jvm.json

{
  "createdAt": "2019-12-12T05:47:17Z",
  "defaultBranch": "master",
  "description": "JVM in Rust, written as a learning project.",
  "fullName": "douchuan/jvm",
  "homepage": "",
  "language": "Rust",
  "name": "jvm",
  "pushedAt": "2021-03-05T15:01:23Z",
  "stargazersCount": 529,
  "topics": [
    "java",
    "jvm",
    "modular",
    "rust",
    "vm"
  ],
  "updatedAt": "2025-10-10T23:39:22Z",
  "url": "https://github.com/douchuan/jvm"
}

Have a great goal is a very important thing, such as Moon Landing. What is the meaning of this plan? That’s the process of achieving this goal, the produce of industry and technology.

Sun is a great company, in the era of C++, they created JVM & HotSpot.

Now, we have Rust, a better tool, let’s remake JVM!

Pay tribute to medical workers at the front! Thank you for your contribution to the fight against the epidemic.

Roadmap

• Pass test cases in JDK
• Pass TCK
• GC (crate)
• JIT / interp (crate)
• class verification (crate)
• After GC built, ready for optimize System.arraycopy (the key of performance)
• WebAssembly, make the JVM work in Browser
• java options (-version, -server…)

In summary, the roadmap is built on a 3-step progress.

• Pass TCK
• Refactor & Rewrite
• Divide into several crates, build a collection of modular and reusable vm technologies

Well, it’s a long term plan, Sun spent 30 years to improve VM, Oracle continue doing it.

The journey of a thousand miles begins with one first step. Even the sage was once an ordinary human being.

Just Do It.

Running

# setup JDK
# setup rust toolchain
# clone this project

# compile sample by javac
cd jvm/sample
javac HelloWorld.java
cd ..

# modify r.sh JAVA_HOME according to your env
# exec sample
cd jvm
bash r.sh