diff --git a/Cargo.lock b/Cargo.lock
index ed22f39..db525df 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -940,6 +940,7 @@ dependencies = [
  "librashader-reflect",
  "librashader-runtime",
  "librashader-spirv-cross",
+ "parking_lot",
  "rayon",
  "rustc-hash",
  "thiserror",
diff --git a/README.md b/README.md
index e80f9f6..5e3f868 100644
--- a/README.md
+++ b/README.md
@@ -10,23 +10,21 @@ librashader (*/ˈli:brəʃeɪdɚ/*) is a preprocessor, compiler, and runtime for
 ![Nightly rust](https://img.shields.io/badge/rust-nightly-orange.svg)
 
 ## Supported Render APIs
-librashader supports OpenGL 3, OpenGL 4.6, Vulkan, Direct3D 11, and Direct3D 12.  Older versions
-of Direct3D and OpenGL, as well as Metal, are not supported (but pull-requests are welcome).
+librashader supports OpenGL 3, OpenGL 4.6, Vulkan, Direct3D 11, and Direct3D 12.  Metal and WebGPU
+are not currently supported (but pull-requests are welcome). librashader does not support legacy render
+APIs such as older versions of OpenGL, or legacy versions of Direct3D.
 
 | **API**     | **Status** | **`librashader` feature** |
-|-------------|------------|---------------------------|
-| OpenGL 3.3+ | ✔          | `gl`                      |
-| OpenGL 4.6  | ✔          | `gl`                      |
-| Vulkan      | ✔          | `vk`                      |
-| Direct3D 11 | ✔          | `d3d11`                   |
-| Direct3D 12 | ✔          | `d3d12`                   |
-| OpenGL 2    | ❌          |                           |
-| Direct3D 9  | ❌          |                           |
-| Direct3D 10 | ❌          |                           |
-| Metal       | ❌          |                           |
+|-------------|------------|--------------------------|
+| OpenGL 3.3+ | ✔          | `gl`                     |
+| OpenGL 4.6  | ✔          | `gl`                     |
+| Vulkan      | ✔          | `vk`                     |
+| Direct3D 11 | ✔          | `d3d11`                  |
+| Direct3D 12 | ✔          | `d3d12`                  |
+| Metal       | ❌          |                         |
+| WebGPU      | ❌          |                         |
 
-
-✔ = Render API is supported — 🚧 =  Support is in progress — ❌ Render API is not supported
+✔ = Render API is supported — ❌ Render API is not supported
 ## Usage
 
 librashader provides both a Rust API under the `librashader` crate, and a C API. Both APIs are first-class and fully supported.
@@ -68,9 +66,9 @@ is important to ensure that updates to librashader do not break existing consume
 As of `0.1.0-rc.3`, the C ABI should be mostly stable. We reserve the right to make breaking changes before a numbered
 release without following semantic versioning.
 
-Linking against `librashader.h` directly is possible, but is not officially supported. You will need to ensure linkage
-parameters are correct in order to successfully link with `librashader.lib` or `librashader.a`. The [corrosion](https://github.com/corrosion-rs/)
-CMake package is highly recommended.
+Linking statically against `librashader.h` is possible, but is not officially supported. You will need to ensure 
+linkage parameters are correct in order to successfully link with `librashader.lib` or `librashader.a`. 
+The [corrosion](https://github.com/corrosion-rs/) CMake package is highly recommended.
 
 ### Examples
 
@@ -153,6 +151,13 @@ static GL_DEFAULT_MVP: &[f32; 16] = &[
 ];
 ```
 
+### Thread safety
+In general, it is **safe** to create a filter chain instance from a different thread, but drawing filter passes **must be
+externally synchronized**. The exceptions to filter chain creation are in OpenGL, where creating the filter chain instance
+is safe **if and only if** the thread local OpenGL context is initialized to the same context as the drawing thread, and
+in Direct3D 11, where filter chain creation is thread-unsafe if the `ID3D11Device` was created with 
+`D3D11_CREATE_DEVICE_SINGLETHREADED`.
+
 ### Writing a librashader Runtime
 
 If you wish to contribute a runtime implementation not already available, see the [librashader-runtime](https://docs.rs/librashader-runtime/latest/librashader_runtime/)
diff --git a/include/librashader.h b/include/librashader.h
index 7005e7b..ebb6c87 100644
--- a/include/librashader.h
+++ b/include/librashader.h
@@ -831,6 +831,10 @@ libra_error_t libra_gl_filter_chain_create(libra_shader_preset_t *preset,
 ///    values for the model view projection matrix.
 /// - `opt` may be null, or if it is not null, must be an aligned pointer to a valid `frame_gl_opt_t`
 ///    struct.
+/// - You must ensure that only one thread has access to `chain` before you call this function. Only one
+///   thread at a time may call this function. The thread `libra_gl_filter_chain_frame` is called from
+///   must have its thread-local OpenGL context initialized with the same context used to create
+///   the filter chain.
 libra_error_t libra_gl_filter_chain_frame(libra_gl_filter_chain_t *chain,
                                           size_t frame_count,
                                           struct libra_source_image_gl_t image,
@@ -925,6 +929,8 @@ libra_error_t libra_vk_filter_chain_create(struct libra_device_vk_t vulkan,
 ///    values for the model view projection matrix.
 /// - `opt` may be null, or if it is not null, must be an aligned pointer to a valid `frame_vk_opt_t`
 ///    struct.
+/// - You must ensure that only one thread has access to `chain` before you call this function. Only one
+///   thread at a time may call this function.
 libra_error_t libra_vk_filter_chain_frame(libra_vk_filter_chain_t *chain,
                                           VkCommandBuffer command_buffer,
                                           size_t frame_count,
@@ -1015,6 +1021,8 @@ libra_error_t libra_d3d11_filter_chain_create(libra_shader_preset_t *preset,
 ///    struct.
 /// - `out` must not be null.
 /// - `image.handle` must not be null.
+/// - You must ensure that only one thread has access to `chain` before you call this function. Only one
+///   thread at a time may call this function.
 libra_error_t libra_d3d11_filter_chain_frame(libra_d3d11_filter_chain_t *chain,
                                              size_t frame_count,
                                              struct libra_source_image_d3d11_t image,
@@ -1106,6 +1114,8 @@ libra_error_t libra_d3d12_filter_chain_create(libra_shader_preset_t *preset,
 /// - `out` must be a descriptor handle to a render target view.
 /// - `image.resource` must not be null.
 /// - `command_list` must not be null.
+/// - You must ensure that only one thread has access to `chain` before you call this function. Only one
+///   thread at a time may call this function.
 libra_error_t libra_d3d12_filter_chain_frame(libra_d3d12_filter_chain_t *chain,
                                              const ID3D12GraphicsCommandList * command_list,
                                              size_t frame_count,
diff --git a/librashader-capi/src/lib.rs b/librashader-capi/src/lib.rs
index a48c7b2..9ec6fcb 100644
--- a/librashader-capi/src/lib.rs
+++ b/librashader-capi/src/lib.rs
@@ -51,6 +51,18 @@
 //! There is a case to be made for skipping error checking for `*_filter_chain_frame` due to performance reasons,
 //! but only if you are certain that the safety invariants are upheld on each call. Failure to check for errors
 //! may result in **undefined behaviour** stemming from failure to uphold safety invariants.
+//!
+//! ## Thread safety
+//!
+//! In general, it is **safe** to create a filter chain instance from a different thread, but drawing filter passes must be
+//! synchronized externally. The exception to filter chain creation are in OpenGL, where creating the filter chain instance
+//! is safe **if and only if** the thread local OpenGL context is initialized to the same context as the drawing thread, and
+//! in Direct3D 11, where filter chain creation is unsafe if the `ID3D11Device` was created with
+//! `D3D11_CREATE_DEVICE_SINGLETHREADED`.
+//!
+//! You must ensure that only thread has access to a created filter pass **before** you call `*_frame`. `*_frame` may only be
+//! called from one thread at a time.
+
 #![allow(non_camel_case_types)]
 #![feature(try_blocks)]
 #![feature(pointer_is_aligned)]
@@ -73,3 +85,6 @@ pub type LIBRASHADER_API_VERSION = usize;
 /// The current version of the librashader API/ABI.
 /// Pass this into `version` for config structs.
 pub const LIBRASHADER_CURRENT_VERSION: LIBRASHADER_API_VERSION = 0;
+
+#[allow(dead_code)]
+const fn assert_thread_safe<T: Send + Sync>() { }
diff --git a/librashader-capi/src/presets.rs b/librashader-capi/src/presets.rs
index ebd3139..4179741 100644
--- a/librashader-capi/src/presets.rs
+++ b/librashader-capi/src/presets.rs
@@ -7,6 +7,8 @@ use std::ffi::{c_char, CStr, CString};
 use std::mem::MaybeUninit;
 use std::ptr::NonNull;
 
+const _: () = crate::assert_thread_safe::<ShaderPreset>();
+
 /// A list of preset parameters.
 #[repr(C)]
 pub struct libra_preset_param_list_t {
diff --git a/librashader-capi/src/runtime/d3d11/filter_chain.rs b/librashader-capi/src/runtime/d3d11/filter_chain.rs
index 288fc24..7729d0e 100644
--- a/librashader-capi/src/runtime/d3d11/filter_chain.rs
+++ b/librashader-capi/src/runtime/d3d11/filter_chain.rs
@@ -13,8 +13,8 @@ use windows::Win32::Graphics::Direct3D11::{
     ID3D11Device, ID3D11RenderTargetView, ID3D11ShaderResourceView,
 };
 
-pub use librashader::runtime::d3d11::capi::options::FilterChainOptionsD3D11;
-pub use librashader::runtime::d3d11::capi::options::FrameOptionsD3D11;
+use librashader::runtime::d3d11::capi::options::FilterChainOptionsD3D11;
+use librashader::runtime::d3d11::capi::options::FrameOptionsD3D11;
 
 use librashader::runtime::{FilterChainParameters, Size, Viewport};
 use crate::LIBRASHADER_API_VERSION;
@@ -142,6 +142,8 @@ extern_fn! {
     ///    struct.
     /// - `out` must not be null.
     /// - `image.handle` must not be null.
+    /// - You must ensure that only one thread has access to `chain` before you call this function. Only one
+    ///   thread at a time may call this function.
     fn libra_d3d11_filter_chain_frame(
         chain: *mut libra_d3d11_filter_chain_t,
         frame_count: usize,
diff --git a/librashader-capi/src/runtime/d3d11/mod.rs b/librashader-capi/src/runtime/d3d11/mod.rs
index 7db6582..5557f2b 100644
--- a/librashader-capi/src/runtime/d3d11/mod.rs
+++ b/librashader-capi/src/runtime/d3d11/mod.rs
@@ -2,3 +2,4 @@
 
 mod filter_chain;
 pub use filter_chain::*;
+const _: () = crate::assert_thread_safe::<librashader::runtime::d3d11::FilterChain>();
diff --git a/librashader-capi/src/runtime/d3d12/filter_chain.rs b/librashader-capi/src/runtime/d3d12/filter_chain.rs
index 6bef61e..c85ea66 100644
--- a/librashader-capi/src/runtime/d3d12/filter_chain.rs
+++ b/librashader-capi/src/runtime/d3d12/filter_chain.rs
@@ -13,8 +13,8 @@ use windows::Win32::Graphics::Direct3D12::{
 };
 use windows::Win32::Graphics::Dxgi::Common::DXGI_FORMAT;
 
-pub use librashader::runtime::d3d12::capi::options::FilterChainOptionsD3D12;
-pub use librashader::runtime::d3d12::capi::options::FrameOptionsD3D12;
+use librashader::runtime::d3d12::capi::options::FilterChainOptionsD3D12;
+use librashader::runtime::d3d12::capi::options::FrameOptionsD3D12;
 
 use librashader::runtime::d3d12::{D3D12InputImage, D3D12OutputView};
 use librashader::runtime::{FilterChainParameters, Size, Viewport};
@@ -159,6 +159,8 @@ extern_fn! {
     /// - `out` must be a descriptor handle to a render target view.
     /// - `image.resource` must not be null.
     /// - `command_list` must not be null.
+    /// - You must ensure that only one thread has access to `chain` before you call this function. Only one
+    ///   thread at a time may call this function.
     fn libra_d3d12_filter_chain_frame(
         chain: *mut libra_d3d12_filter_chain_t,
         command_list: ManuallyDrop<ID3D12GraphicsCommandList>,
diff --git a/librashader-capi/src/runtime/d3d12/mod.rs b/librashader-capi/src/runtime/d3d12/mod.rs
index 2201178..3c6ecda 100644
--- a/librashader-capi/src/runtime/d3d12/mod.rs
+++ b/librashader-capi/src/runtime/d3d12/mod.rs
@@ -2,3 +2,4 @@
 
 mod filter_chain;
 pub use filter_chain::*;
+const _: () = crate::assert_thread_safe::<librashader::runtime::d3d12::FilterChain>();
diff --git a/librashader-capi/src/runtime/gl/filter_chain.rs b/librashader-capi/src/runtime/gl/filter_chain.rs
index cd64a31..cf3728d 100644
--- a/librashader-capi/src/runtime/gl/filter_chain.rs
+++ b/librashader-capi/src/runtime/gl/filter_chain.rs
@@ -10,8 +10,8 @@ use std::mem::MaybeUninit;
 use std::ptr::NonNull;
 use std::slice;
 
-pub use librashader::runtime::gl::capi::options::FilterChainOptionsGL;
-pub use librashader::runtime::gl::capi::options::FrameOptionsGL;
+use librashader::runtime::gl::capi::options::FilterChainOptionsGL;
+use librashader::runtime::gl::capi::options::FrameOptionsGL;
 use librashader::runtime::FilterChainParameters;
 use librashader::runtime::{Size, Viewport};
 use crate::LIBRASHADER_API_VERSION;
@@ -162,6 +162,10 @@ extern_fn! {
     ///    values for the model view projection matrix.
     /// - `opt` may be null, or if it is not null, must be an aligned pointer to a valid `frame_gl_opt_t`
     ///    struct.
+    /// - You must ensure that only one thread has access to `chain` before you call this function. Only one
+    ///   thread at a time may call this function. The thread `libra_gl_filter_chain_frame` is called from
+    ///   must have its thread-local OpenGL context initialized with the same context used to create
+    ///   the filter chain.
     fn libra_gl_filter_chain_frame(
         chain: *mut libra_gl_filter_chain_t,
         frame_count: usize,
diff --git a/librashader-capi/src/runtime/gl/mod.rs b/librashader-capi/src/runtime/gl/mod.rs
index 1699556..f33b437 100644
--- a/librashader-capi/src/runtime/gl/mod.rs
+++ b/librashader-capi/src/runtime/gl/mod.rs
@@ -2,3 +2,4 @@
 
 mod filter_chain;
 pub use filter_chain::*;
+const _: () = crate::assert_thread_safe::<librashader::runtime::gl::FilterChain>();
diff --git a/librashader-capi/src/runtime/vk/filter_chain.rs b/librashader-capi/src/runtime/vk/filter_chain.rs
index 002f8fb..5666b7c 100644
--- a/librashader-capi/src/runtime/vk/filter_chain.rs
+++ b/librashader-capi/src/runtime/vk/filter_chain.rs
@@ -10,8 +10,8 @@ use std::mem::MaybeUninit;
 use std::ptr::NonNull;
 use std::slice;
 
-pub use librashader::runtime::vk::capi::options::FilterChainOptionsVulkan;
-pub use librashader::runtime::vk::capi::options::FrameOptionsVulkan;
+use librashader::runtime::vk::capi::options::FilterChainOptionsVulkan;
+use librashader::runtime::vk::capi::options::FrameOptionsVulkan;
 use librashader::runtime::FilterChainParameters;
 use librashader::runtime::{Size, Viewport};
 
@@ -182,6 +182,8 @@ extern_fn! {
     ///    values for the model view projection matrix.
     /// - `opt` may be null, or if it is not null, must be an aligned pointer to a valid `frame_vk_opt_t`
     ///    struct.
+    /// - You must ensure that only one thread has access to `chain` before you call this function. Only one
+    ///   thread at a time may call this function.
     fn libra_vk_filter_chain_frame(
         chain: *mut libra_vk_filter_chain_t,
         command_buffer: vk::CommandBuffer,
diff --git a/librashader-capi/src/runtime/vk/mod.rs b/librashader-capi/src/runtime/vk/mod.rs
index 1699556..167e387 100644
--- a/librashader-capi/src/runtime/vk/mod.rs
+++ b/librashader-capi/src/runtime/vk/mod.rs
@@ -2,3 +2,4 @@
 
 mod filter_chain;
 pub use filter_chain::*;
+const _: () = crate::assert_thread_safe::<librashader::runtime::vk::FilterChain>();
diff --git a/librashader-runtime-d3d12/Cargo.toml b/librashader-runtime-d3d12/Cargo.toml
index 10a297a..733da98 100644
--- a/librashader-runtime-d3d12/Cargo.toml
+++ b/librashader-runtime-d3d12/Cargo.toml
@@ -19,6 +19,7 @@ librashader-reflect = { path = "../librashader-reflect", version = "0.1.0-rc.2",
 librashader-runtime = { path = "../librashader-runtime", version = "0.1.0-rc.2" }
 thiserror = "1.0.37"
 spirv_cross = { package = "librashader-spirv-cross", version = "0.23" }
+parking_lot = "0.12.1"
 
 rustc-hash = "1.1.0"
 bytemuck = { version = "1.12.3", features = ["derive"] }
diff --git a/librashader-runtime-d3d12/src/buffer.rs b/librashader-runtime-d3d12/src/buffer.rs
index 6a79028..72e9fe7 100644
--- a/librashader-runtime-d3d12/src/buffer.rs
+++ b/librashader-runtime-d3d12/src/buffer.rs
@@ -100,8 +100,10 @@ impl D3D12Buffer {
 
 /// SAFETY: Creating the pointer should be safe in multithreaded contexts.
 ///
-/// Mutation is guarded by DerefMut<Target=[u8]>
+/// Mutation is guarded by DerefMut<Target=[u8]>, so exclusive access is guaranteed.
+/// We do not ever leak the pointer to C.
 unsafe impl Send for RawD3D12Buffer {}
+unsafe impl Sync for RawD3D12Buffer {}
 pub struct RawD3D12Buffer {
     buffer: ManuallyDrop<D3D12Buffer>,
     ptr: NonNull<c_void>,
diff --git a/librashader-runtime-d3d12/src/descriptor_heap.rs b/librashader-runtime-d3d12/src/descriptor_heap.rs
index f9169af..0c62a0c 100644
--- a/librashader-runtime-d3d12/src/descriptor_heap.rs
+++ b/librashader-runtime-d3d12/src/descriptor_heap.rs
@@ -1,10 +1,10 @@
 use crate::error;
 use bitvec::bitvec;
 use bitvec::boxed::BitBox;
-use std::cell::RefCell;
+use parking_lot::RwLock;
 use std::marker::PhantomData;
 use std::ops::Deref;
-use std::rc::Rc;
+use std::sync::Arc;
 
 use crate::error::FilterChainError;
 use windows::Win32::Graphics::Direct3D12::{
@@ -98,12 +98,12 @@ impl const D3D12HeapType for SamplerWorkHeap {
     }
 }
 
-pub type D3D12DescriptorHeapSlot<T> = Rc<D3D12DescriptorHeapSlotInner<T>>;
+pub type D3D12DescriptorHeapSlot<T> = Arc<D3D12DescriptorHeapSlotInner<T>>;
 
 pub struct D3D12DescriptorHeapSlotInner<T> {
     cpu_handle: D3D12_CPU_DESCRIPTOR_HANDLE,
     gpu_handle: Option<D3D12_GPU_DESCRIPTOR_HANDLE>,
-    heap: Rc<RefCell<D3D12DescriptorHeapInner>>,
+    heap: Arc<RwLock<D3D12DescriptorHeapInner>>,
     slot: usize,
     _pd: PhantomData<T>,
 }
@@ -117,7 +117,7 @@ impl<T> D3D12DescriptorHeapSlotInner<T> {
     /// unsafe because type must match
     pub unsafe fn copy_descriptor(&self, source: D3D12_CPU_DESCRIPTOR_HANDLE) {
         unsafe {
-            let heap = self.heap.deref().borrow();
+            let heap = self.heap.deref().read();
 
             heap.device
                 .CopyDescriptorsSimple(1, self.cpu_handle, source, heap.ty)
@@ -142,7 +142,7 @@ impl<T: D3D12ShaderVisibleHeapType> AsRef<D3D12_GPU_DESCRIPTOR_HANDLE>
 
 impl<T: D3D12ShaderVisibleHeapType> From<&D3D12DescriptorHeap<T>> for ID3D12DescriptorHeap {
     fn from(value: &D3D12DescriptorHeap<T>) -> Self {
-        value.0.borrow().heap.clone()
+        value.0.read().heap.clone()
     }
 }
 
@@ -159,7 +159,7 @@ struct D3D12DescriptorHeapInner {
     map: BitBox,
 }
 
-pub struct D3D12DescriptorHeap<T>(Rc<RefCell<D3D12DescriptorHeapInner>>, PhantomData<T>);
+pub struct D3D12DescriptorHeap<T>(Arc<RwLock<D3D12DescriptorHeapInner>>, PhantomData<T>);
 
 impl<T: D3D12HeapType> D3D12DescriptorHeap<T> {
     pub fn new(device: &ID3D12Device, size: usize) -> error::Result<D3D12DescriptorHeap<T>> {
@@ -171,7 +171,7 @@ impl<T: D3D12HeapType> D3D12DescriptorHeap<T> {
 impl<T> D3D12DescriptorHeap<T> {
     /// Gets a cloned handle to the inner heap
     pub fn handle(&self) -> ID3D12DescriptorHeap {
-        let inner = self.0.borrow();
+        let inner = self.0.read();
         inner.heap.clone()
     }
 
@@ -190,7 +190,7 @@ impl<T> D3D12DescriptorHeap<T> {
             };
 
             Ok(D3D12DescriptorHeap(
-                Rc::new(RefCell::new(D3D12DescriptorHeapInner {
+                Arc::new(RwLock::new(D3D12DescriptorHeapInner {
                     device: device.clone(),
                     heap,
                     ty: desc.Type,
@@ -224,12 +224,12 @@ impl<T> D3D12DescriptorHeap<T> {
     ) {
         // has to be called right after creation.
         assert_eq!(
-            Rc::strong_count(&self.0),
+            Arc::strong_count(&self.0),
             1,
             "D3D12DescriptorHeap::suballocate can only be callled immediately after creation."
         );
 
-        let inner = Rc::try_unwrap(self.0)
+        let inner = Arc::try_unwrap(self.0)
             .expect("[d3d12] undefined behaviour to suballocate a descriptor heap with live descriptors.")
             .into_inner();
 
@@ -301,11 +301,11 @@ impl<T> D3D12DescriptorHeap<T> {
             heaps
                 .into_iter()
                 .map(|inner| {
-                    D3D12DescriptorHeap(Rc::new(RefCell::new(inner)), PhantomData::default())
+                    D3D12DescriptorHeap(Arc::new(RwLock::new(inner)), PhantomData::default())
                 })
                 .collect(),
             reserved_heap.map(|inner| {
-                D3D12DescriptorHeap(Rc::new(RefCell::new(inner)), PhantomData::default())
+                D3D12DescriptorHeap(Arc::new(RwLock::new(inner)), PhantomData::default())
             }),
             inner.heap,
         )
@@ -314,7 +314,7 @@ impl<T> D3D12DescriptorHeap<T> {
     pub fn alloc_slot(&mut self) -> error::Result<D3D12DescriptorHeapSlot<T>> {
         let mut handle = D3D12_CPU_DESCRIPTOR_HANDLE { ptr: 0 };
 
-        let mut inner = self.0.borrow_mut();
+        let mut inner = self.0.write();
         for i in inner.start..inner.num_descriptors {
             if !inner.map[i] {
                 inner.map.set(i, true);
@@ -327,10 +327,10 @@ impl<T> D3D12DescriptorHeap<T> {
                         ptr: (handle.ptr as u64 - inner.cpu_start.ptr as u64) + gpu_start.ptr,
                     });
 
-                return Ok(Rc::new(D3D12DescriptorHeapSlotInner {
+                return Ok(Arc::new(D3D12DescriptorHeapSlotInner {
                     cpu_handle: handle,
                     slot: i,
-                    heap: Rc::clone(&self.0),
+                    heap: Arc::clone(&self.0),
                     gpu_handle,
                     _pd: Default::default(),
                 }));
@@ -352,7 +352,7 @@ impl<T> D3D12DescriptorHeap<T> {
 
 impl<T> Drop for D3D12DescriptorHeapSlotInner<T> {
     fn drop(&mut self) {
-        let mut inner = self.heap.borrow_mut();
+        let mut inner = self.heap.write();
         inner.map.set(self.slot, false);
         if inner.start > self.slot {
             inner.start = self.slot
diff --git a/librashader-runtime-d3d12/src/filter_chain.rs b/librashader-runtime-d3d12/src/filter_chain.rs
index 887e57c..f40c917 100644
--- a/librashader-runtime-d3d12/src/filter_chain.rs
+++ b/librashader-runtime-d3d12/src/filter_chain.rs
@@ -403,6 +403,8 @@ impl FilterChainD3D12 {
 
         let filters: Vec<error::Result<_>> = passes.into_par_iter()
             .zip(hlsl_passes)
+            .zip(work_heaps)
+            .zip(sampler_work_heaps)
             .enumerate()
             .map_init(
                 || {
@@ -411,8 +413,8 @@ impl FilterChainD3D12 {
                     let compiler: IDxcCompiler = unsafe { DxcCreateInstance(&CLSID_DxcCompiler)? };
                     Ok::<_, FilterChainError>((validator, library, compiler))
                 },
-                |dxc, (index, ((config, source, mut dxil),
-                          (_, _, mut hlsl)))| {
+                |dxc, (index, ((((config, source, mut dxil),
+                          (_, _, mut hlsl)), mut texture_heap), mut sampler_heap))| {
                 let Ok((validator, library, compiler)) = dxc else {
                     return Err(FilterChainError::Direct3DOperationError("Could not initialize DXC for thread"));
                 };
@@ -472,48 +474,55 @@ impl FilterChainD3D12 {
 
                 let uniform_bindings = reflection.meta.create_binding_map(|param| param.offset());
 
-                Ok((reflection,
-                    uniform_bindings,
-                    uniform_storage,
-                    graphics_pipeline,
-                    config,
-                    source))
-
-            }).collect();
-
-        let filters: error::Result<Vec<_>> = filters.into_iter().collect();
-        let filters = filters?;
-
-        // Need to take care of the heaps in a single thread because [;16] is not sized..?
-        let filters: Vec<error::Result<FilterPass>> = filters
-            .into_iter()
-            .zip(work_heaps)
-            .zip(sampler_work_heaps)
-            .map(
-                |(
-                    (
-                        (reflection, uniform_bindings, uniform_storage, pipeline, config, source),
-                        mut texture_heap,
-                    ),
-                    mut sampler_heap,
-                )| {
                     let texture_heap = texture_heap.alloc_range()?;
                     let sampler_heap = sampler_heap.alloc_range()?;
+
                     Ok(FilterPass {
                         reflection,
                         uniform_bindings,
                         uniform_storage,
-                        pipeline,
+                        pipeline: graphics_pipeline,
                         config,
                         texture_heap,
                         sampler_heap,
                         source,
                     })
-                },
-            )
-            .collect();
+
+            }).collect();
+
         let filters: error::Result<Vec<_>> = filters.into_iter().collect();
         let filters = filters?;
+        //
+        // // Need to take care of the heaps in a single thread because [;16] is not sized..?
+        // let filters: Vec<error::Result<FilterPass>> = filters
+        //     .into_iter()
+        //     .zip(work_heaps)
+        //     .zip(sampler_work_heaps)
+        //     .map(
+        //         |(
+        //             (
+        //                 (reflection, uniform_bindings, uniform_storage, pipeline, config, source),
+        //                 mut texture_heap,
+        //             ),
+        //             mut sampler_heap,
+        //         )| {
+        //             let texture_heap = texture_heap.alloc_range()?;
+        //             let sampler_heap = sampler_heap.alloc_range()?;
+        //             Ok(FilterPass {
+        //                 reflection,
+        //                 uniform_bindings,
+        //                 uniform_storage,
+        //                 pipeline,
+        //                 config,
+        //                 texture_heap,
+        //                 sampler_heap,
+        //                 source,
+        //             })
+        //         },
+        //     )
+        //     .collect();
+        // let filters: error::Result<Vec<_>> = filters.into_iter().collect();
+        // let filters = filters?;
 
         // Panic SAFETY: mipmap_heap is always 1024 descriptors.
         Ok((
diff --git a/librashader-runtime-gl/src/filter_chain/filter_impl.rs b/librashader-runtime-gl/src/filter_chain/filter_impl.rs
index 2e0bb7c..1047af6 100644
--- a/librashader-runtime-gl/src/filter_chain/filter_impl.rs
+++ b/librashader-runtime-gl/src/filter_chain/filter_impl.rs
@@ -261,7 +261,6 @@ impl<T: GLInterface> FilterChainImpl<T> {
 
             filters.push(FilterPass {
                 reflection,
-                compiled: glsl,
                 program,
                 ubo_location,
                 ubo_ring,
diff --git a/librashader-runtime-gl/src/filter_pass.rs b/librashader-runtime-gl/src/filter_pass.rs
index 785005d..658f3f5 100644
--- a/librashader-runtime-gl/src/filter_pass.rs
+++ b/librashader-runtime-gl/src/filter_pass.rs
@@ -1,6 +1,4 @@
 use gl::types::{GLint, GLsizei, GLuint};
-use librashader_reflect::back::cross::CrossGlslContext;
-use librashader_reflect::back::ShaderCompilerOutput;
 use librashader_reflect::reflect::ShaderReflection;
 
 use librashader_common::{ImageFormat, Size, Viewport};
@@ -33,7 +31,6 @@ impl UniformOffset {
 
 pub struct FilterPass<T: GLInterface> {
     pub reflection: ShaderReflection,
-    pub compiled: ShaderCompilerOutput<String, CrossGlslContext>,
     pub program: GLuint,
     pub ubo_location: UniformLocation<GLuint>,
     pub ubo_ring: Option<T::UboRing>,
diff --git a/librashader-runtime-vk/src/memory.rs b/librashader-runtime-vk/src/memory.rs
index d922461..e97459b 100644
--- a/librashader-runtime-vk/src/memory.rs
+++ b/librashader-runtime-vk/src/memory.rs
@@ -130,8 +130,10 @@ impl Drop for VulkanBuffer {
 
 /// SAFETY: Creating the pointer should be safe in multithreaded contexts.
 ///
-/// Mutation is guarded by DerefMut<Target=[u8]>
+/// Mutation is guarded by DerefMut<Target=[u8]>, so exclusive access is guaranteed.
+/// We do not ever leak the pointer to C.
 unsafe impl Send for RawVulkanBuffer {}
+unsafe impl Sync for RawVulkanBuffer {}
 pub struct RawVulkanBuffer {
     buffer: ManuallyDrop<VulkanBuffer>,
     ptr: NonNull<c_void>,
diff --git a/librashader/src/lib.rs b/librashader/src/lib.rs
index 2992035..63d45a1 100644
--- a/librashader/src/lib.rs
+++ b/librashader/src/lib.rs
@@ -26,16 +26,13 @@
 //!
 //! | **API**     | **Status** | **`librashader` feature** |
 //! |-------------|------------|---------------------------|
-//! | OpenGL 3.3+ | ✔         | `gl`                     |
-//! | OpenGL 4.6  | ✔         | `gl`                     |
+//! | OpenGL 3.3+ | ✔         | `gl`                      |
+//! | OpenGL 4.6  | ✔         | `gl`                      |
 //! | Vulkan      | ✔         | `vk`                     |
-//! | Direct3D 11  | ✔         | `d3d11`                  |
-//! | Direct3D 12  | ✔         | `d3d12`                  |
-//! | OpenGL 2    | ❌         |                          |
-//! | Direct3D 9   | ❌         |                          |
-//! | Direct3D 10   | ❌         |                          |
-//! | Metal       | ❌         |                          |
-//!
+//! | Direct3D 11  | ✔        | `d3d11`                 |
+//! | Direct3D 12  | ✔        | `d3d12`                 |
+//! | Metal       | ❌        |                         |
+//! | WebGPU      | ❌        |                        |
 //! ## C API
 //! For documentation on the librashader C API, see [librashader-capi](https://docs.rs/librashader-capi/latest/librashader_capi/),
 //! or [`librashader.h`](https://github.com/SnowflakePowered/librashader/blob/master/include/librashader.h).