diff --git a/Cargo.toml b/Cargo.toml
index 12f86fb..a9e36f6 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,5 +10,7 @@ members = [
     "u144",
     "u160",
     "publish-ws",
-    "yagen"
+    "yagen",
+    "xpcom",
+    "xpcom/tool"
 ]
diff --git a/publish-ws/Cargo.toml b/publish-ws/Cargo.toml
index a2184b6..7f8afb2 100644
--- a/publish-ws/Cargo.toml
+++ b/publish-ws/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "publish-ws"
-version = "0.1.9"
+version = "0.1.10"
 authors = ["natfoam"]
 edition = "2021"
 description = "Publish Workspace Packages"
@@ -11,5 +11,5 @@ repository = "https://github.com/natfoam/lib"
 
 [dependencies]
 toml = "0.5.9"
-serde = "1.0.137"
-serde_derive = "1.0.137"
\ No newline at end of file
+serde = "1.0.138"
+serde_derive = "1.0.138"
\ No newline at end of file
diff --git a/xpcom/Cargo.toml b/xpcom/Cargo.toml
new file mode 100644
index 0000000..62e427b
--- /dev/null
+++ b/xpcom/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "xpcom"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
diff --git a/xpcom/src/lib.rs b/xpcom/src/lib.rs
new file mode 100644
index 0000000..e1626ef
--- /dev/null
+++ b/xpcom/src/lib.rs
@@ -0,0 +1,130 @@
+use std::{
+    ptr::null_mut,
+    sync::atomic::{AtomicU32, Ordering},
+};
+
+type HRESULT = u32;
+
+const S_OK: HRESULT = 0;
+const E_NOINTERFACE: HRESULT = 0x80004002;
+const E_POINTER: HRESULT = 0x80004003;
+
+type GUID = u128;
+
+type ULONG = u32;
+
+//
+
+pub trait Interface: 'static {
+    const ID: GUID;
+}
+
+#[repr(transparent)]
+pub struct Obj<I: Interface>(&'static Vmt<Obj<I>, I>);
+
+#[allow(non_snake_case)]
+#[repr(C)]
+struct Vmt<T, I: Interface> {
+    QueryInterface:
+        extern "stdcall" fn(this: &mut T, riid: &GUID, ppvObject: *mut *mut T) -> HRESULT,
+    AddRef: extern "stdcall" fn(this: &mut T) -> ULONG,
+    Release: extern "stdcall" fn(this: &mut T) -> ULONG,
+    interface: I,
+}
+
+#[repr(transparent)]
+pub struct Ref<I: Interface>(*mut Obj<I>);
+
+impl<I: Interface> Ref<I> {
+    pub fn raw(&self) -> &mut Obj<I> {
+        unsafe { &mut *self.0 }
+    }
+    pub fn new(raw: &mut Obj<I>) -> Self {
+        (raw.0.AddRef)(raw);
+        Self(raw)
+    }
+}
+
+impl<I: Interface> Drop for Ref<I> {
+    fn drop(&mut self) {
+        let raw = self.raw();
+        (raw.0.Release)(raw);
+    }
+}
+
+impl<I: Interface> Clone for Ref<I> {
+    fn clone(&self) -> Self {
+        Self::new(self.raw())
+    }
+}
+
+//
+
+pub trait Class: 'static + Sized {
+    type Interface: Interface;
+    const INTERFACE: Self::Interface;
+}
+
+#[repr(C)]
+struct ClassObj<C: Class> {
+    vmt: Box<Vmt<Self, C::Interface>>,
+    counter: AtomicU32,
+    value: C,
+}
+
+impl<C: Class> ClassObj<C> {
+    fn new(value: C) -> Box<Self> {
+        Box::new(ClassObj {
+            vmt: Box::new(Vmt {
+                QueryInterface: ClassObj::QueryInterface,
+                AddRef: ClassObj::AddRef,
+                Release: ClassObj::Release,
+                interface: C::INTERFACE,
+            }),
+            counter: AtomicU32::default(),
+            value,
+        })
+    }
+    extern "stdcall" fn QueryInterface(
+        &mut self,
+        riid: &GUID,
+        ppvObject: *mut *mut Self,
+    ) -> HRESULT {
+        if ppvObject == null_mut() {
+            return E_POINTER;
+        }
+        let result: (*mut Self, HRESULT) = if C::Interface::ID == *riid {
+            self.AddRef();
+            (self, S_OK)
+        } else {
+            (null_mut(), E_NOINTERFACE)
+        };
+        unsafe { *ppvObject = result.0 }
+        result.1
+    }
+    extern "stdcall" fn AddRef(&mut self) -> ULONG {
+        self.counter.fetch_add(1, Ordering::Relaxed) + 1
+    }
+    extern "stdcall" fn Release(&mut self) -> ULONG {
+        match self.counter.fetch_sub(1, Ordering::Relaxed) {
+            0 => panic!("release"),
+            1 => {
+                unsafe { Box::from_raw(self) };
+                0
+            }
+            c => c - 1,
+        }
+    }
+}
+
+pub fn new<C: Class>(value: C) -> Ref<C::Interface> {
+    let i = Box::into_raw(ClassObj::new(value)) as *mut Obj<C::Interface>;
+    Ref::new(unsafe { &mut *i })
+}
+
+#[cfg(test)]
+mod tests {
+
+    #[test]
+    fn it_works() {}
+}
diff --git a/xpcom/tool/Cargo.toml b/xpcom/tool/Cargo.toml
new file mode 100644
index 0000000..4af233f
--- /dev/null
+++ b/xpcom/tool/Cargo.toml
@@ -0,0 +1,12 @@
+[package]
+name = "xpcom-tool"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+serde = "1.0.138"
+serde_derive = "1.0.138"
+serde_json = "1.0.82"
+serde_yaml = "0.8.24"
diff --git a/xpcom/tool/src/guid.rs b/xpcom/tool/src/guid.rs
new file mode 100644
index 0000000..52c4ef3
--- /dev/null
+++ b/xpcom/tool/src/guid.rs
@@ -0,0 +1,46 @@
+use serde::{
+    de::{Error, Visitor},
+    Deserialize, Serialize,
+};
+
+pub struct Guid(pub u128);
+
+impl Serialize for Guid {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: serde::Serializer,
+    {
+        serializer.serialize_str(format!("{:X}", self.0).as_str())
+    }
+}
+
+struct StringVisitor;
+
+impl<'de> Visitor<'de> for StringVisitor {
+    type Value = String;
+
+    fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+        formatter.write_str("a string GUID")
+    }
+
+    fn visit_string<E>(self, v: String) -> Result<Self::Value, E>
+    where
+        E: Error,
+    {
+        Ok(v)
+    }
+}
+
+impl<'de> Deserialize<'de> for Guid {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let s = deserializer.deserialize_string(StringVisitor)?;
+        let x = u128::from_str_radix(s.as_str(), 16);
+        match x {
+            Ok(v) => Ok(Guid(v)),
+            Err(e) => Err(D::Error::custom(e)),
+        }
+    }
+}
diff --git a/xpcom/tool/src/main.rs b/xpcom/tool/src/main.rs
new file mode 100644
index 0000000..2000c22
--- /dev/null
+++ b/xpcom/tool/src/main.rs
@@ -0,0 +1,19 @@
+mod guid;
+mod types;
+
+use crate::types::{interface, method, param, ptr, struct_, Library, Type};
+
+fn main() {
+    let library = Library::from([
+        struct_("S", &[param("begin", Type::U8)]),
+        interface(
+            "IMy",
+            0xFFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF_FFFF,
+            &[method("GetValue", &[], ptr(Type::U32))],
+        ),
+    ]);
+
+    // let x = serde_json::to_string(&library).unwrap();
+    let x = serde_yaml::to_string(&library).unwrap();
+    println!("{}", x);
+}
diff --git a/xpcom/tool/src/types/mod.rs b/xpcom/tool/src/types/mod.rs
new file mode 100644
index 0000000..d9c2312
--- /dev/null
+++ b/xpcom/tool/src/types/mod.rs
@@ -0,0 +1,79 @@
+use std::collections::HashMap;
+
+use serde_derive::{Deserialize, Serialize};
+
+use crate::guid::Guid;
+
+#[derive(Serialize, Deserialize, Clone)]
+pub enum Type {
+    I8,
+    U8,
+    I16,
+    U16,
+    I32,
+    U32,
+    I64,
+    U64,
+    Ptr(Box<Type>),
+    Id(String),
+}
+
+#[derive(Serialize, Deserialize, Clone)]
+pub struct Param {
+    name: String,
+    r#type: Type,
+}
+
+#[derive(Serialize, Deserialize, Clone)]
+pub struct Method {
+    name: String,
+    params: Vec<Param>,
+    result: Type,
+}
+
+type Struct = Vec<Param>;
+
+#[derive(Serialize, Deserialize)]
+pub enum TypeDef {
+    Struct(Struct),
+    Interface { guid: Guid, methods: Vec<Method> },
+}
+
+fn type_def(name: &str, def: TypeDef) -> (String, TypeDef) {
+    (name.to_string(), def)
+}
+
+pub fn struct_(name: &str, params: &[Param]) -> (String, TypeDef) {
+    type_def(name, TypeDef::Struct(params.to_vec()))
+}
+
+pub fn interface(name: &str, guid: u128, methods: &[Method]) -> (String, TypeDef) {
+    type_def(
+        name,
+        TypeDef::Interface {
+            guid: Guid(guid),
+            methods: methods.to_vec(),
+        },
+    )
+}
+
+pub fn method(name: &str, params: &[Param], result: Type) -> Method {
+    Method {
+        name: name.to_string(),
+        params: params.to_vec(),
+        result,
+    }
+}
+
+pub fn ptr(type_: Type) -> Type {
+    Type::Ptr(Box::new(type_))
+}
+
+pub fn param(name: &str, type_: Type) -> Param {
+    Param {
+        name: name.to_string(),
+        r#type: type_,
+    }
+}
+
+pub type Library = HashMap<String, TypeDef>;