diff --git a/crates/async-compression/Cargo.toml b/crates/async-compression/Cargo.toml
index f85c185b..165a651e 100644
--- a/crates/async-compression/Cargo.toml
+++ b/crates/async-compression/Cargo.toml
@@ -25,6 +25,7 @@ all-algorithms = [
     "gzip",
     "lz4",
     "lzma",
+    "ppmd",
     "xz",
     "xz-parallel",
     "zlib",
@@ -39,6 +40,7 @@ deflate64 = ["compression-codecs/deflate64"]
 gzip = ["compression-codecs/gzip"]
 lz4 = ["compression-codecs/lz4"]
 lzma = ["compression-codecs/lzma"]
+ppmd = ["compression-codecs/ppmd"]
 xz = ["compression-codecs/xz", "lzma"]
 xz-parallel = ["compression-codecs/xz-parallel", "xz"]
 xz2 = ["compression-codecs/xz2", "xz"]
@@ -83,6 +85,7 @@ lz4 = "1.28.1"
 liblzma = "0.4.2"
 zstd-safe = { version = "7", default-features = false }
 deflate64 = "0.1.5"
+ppmd-rust = "1.3.0"
 
 [lints]
 workspace = true
@@ -111,6 +114,10 @@ required-features = ["lz4"]
 name = "lzma"
 required-features = ["lzma"]
 
+[[test]]
+name = "ppmd"
+required-features = ["ppmd"]
+
 [[test]]
 name = "xz"
 required-features = ["xz"]
@@ -142,3 +149,7 @@ required-features = ["zstd", "gzip", "tokio"]
 [[example]]
 name = "lzma_filters"
 required-features = ["xz", "tokio"]
+
+[[example]]
+name = "ppmd_tokio_write"
+required-features = ["ppmd", "tokio"]
diff --git a/crates/async-compression/examples/ppmd_tokio_write.rs b/crates/async-compression/examples/ppmd_tokio_write.rs
new file mode 100644
index 00000000..78fdd161
--- /dev/null
+++ b/crates/async-compression/examples/ppmd_tokio_write.rs
@@ -0,0 +1,29 @@
+use std::io::Result;
+
+use async_compression::tokio::write::{PpmdDecoder, PpmdEncoder};
+use async_compression::Level;
+use tokio::io::AsyncWriteExt as _; // for `write_all` and `shutdown`
+
+#[tokio::main(flavor = "current_thread")]
+async fn main() -> Result<()> {
+    let data = b"example-ppmd";
+    let compressed_data = compress(data).await?;
+    let de_compressed_data = decompress(&compressed_data).await?;
+    assert_eq!(de_compressed_data, data);
+    println!("{}", String::from_utf8(de_compressed_data).unwrap());
+    Ok(())
+}
+
+async fn compress(in_data: &[u8]) -> Result<Vec<u8>> {
+    let mut encoder = PpmdEncoder::with_quality(Vec::new(), Level::Fastest);
+    encoder.write_all(in_data).await?;
+    encoder.shutdown().await?;
+    Ok(encoder.into_inner())
+}
+
+async fn decompress(in_data: &[u8]) -> Result<Vec<u8>> {
+    let mut decoder = PpmdDecoder::new(Vec::new());
+    decoder.write_all(in_data).await?;
+    decoder.shutdown().await?;
+    Ok(decoder.into_inner())
+}
diff --git a/crates/async-compression/src/macros.rs b/crates/async-compression/src/macros.rs
index 75af23cc..b6f5ae14 100644
--- a/crates/async-compression/src/macros.rs
+++ b/crates/async-compression/src/macros.rs
@@ -375,5 +375,20 @@ macro_rules! algos {
         { @dec }
         );
 
+        algos!(@algo ppmd ["ppmd"] PpmdDecoder PpmdEncoder <$inner>
+        { @enc
+
+            pub fn with_quality(inner: $inner, level: crate::core::Level) -> Self {
+                Self {
+                    inner: crate::$($mod::)+generic::Encoder::new(
+                        inner,
+                        crate::codecs::PpmdEncoder::new(level),
+                    ),
+                }
+            }
+        }
+        { @dec }
+        );
+
     }
 }
diff --git a/crates/async-compression/tests/ppmd.rs b/crates/async-compression/tests/ppmd.rs
new file mode 100644
index 00000000..69b4edb7
--- /dev/null
+++ b/crates/async-compression/tests/ppmd.rs
@@ -0,0 +1,4 @@
+#[macro_use]
+mod utils;
+
+test_cases!(ppmd);
diff --git a/crates/async-compression/tests/utils/algos.rs b/crates/async-compression/tests/utils/algos.rs
index 634c47dd..bbe92424 100644
--- a/crates/async-compression/tests/utils/algos.rs
+++ b/crates/async-compression/tests/utils/algos.rs
@@ -229,6 +229,27 @@ algos! {
             }
         }
     }
+
+    pub mod ppmd("ppmd", PpmdEncoder, PpmdDecoder) {
+        pub mod sync {
+            pub use crate::utils::impls::sync::to_vec;
+
+            pub fn compress(bytes: &[u8]) -> Vec<u8> {
+                use std::io::Write;
+                let mut out = Vec::new();
+                let mut enc = ppmd_rust::Ppmd7Encoder::new(&mut out, 8, 4 << 20).unwrap();
+                enc.write_all(bytes).unwrap();
+                let _ = enc.finish(true).unwrap();
+                out
+            }
+
+            pub fn decompress(bytes: &[u8]) -> Vec<u8> {
+                use std::io::Read;
+                let mut dec = ppmd_rust::Ppmd7Decoder::new(bytes, 8, 4 << 20).unwrap();
+                to_vec(&mut dec)
+            }
+        }
+    }
 }
 
 macro_rules! io_algo_parallel {
diff --git a/crates/compression-codecs/Cargo.toml b/crates/compression-codecs/Cargo.toml
index a8142f74..08ca5852 100644
--- a/crates/compression-codecs/Cargo.toml
+++ b/crates/compression-codecs/Cargo.toml
@@ -23,6 +23,7 @@ all-algorithms = [
     "gzip",
     "lz4",
     "lzma",
+    "ppmd",
     "xz-parallel",
     "xz",
     "zlib",
@@ -35,6 +36,7 @@ deflate = ["flate2"]
 gzip = ["flate2", "memchr"]
 lz4 = ["dep:lz4"]
 lzma = ["dep:liblzma"]
+ppmd = ["dep:ppmd_rust"]
 xz = ["lzma"]
 xz-parallel = ["xz", "liblzma/parallel"]
 xz2 = ["xz"]
@@ -55,6 +57,7 @@ libzstd = { package = "zstd", version = "0.13.1", optional = true, default-featu
 lz4 = { version = "1.28.1", optional = true }
 liblzma = { version = "0.4.5", optional = true }
 memchr = { version = "2", optional = true }
+ppmd_rust = { package = "ppmd-rust", version = "1.3.0", optional = true }
 zstd-safe = { version = "7", optional = true, default-features = false }
 
 [lints]
diff --git a/crates/compression-codecs/src/lib.rs b/crates/compression-codecs/src/lib.rs
index 32c186a9..2a72bef8 100644
--- a/crates/compression-codecs/src/lib.rs
+++ b/crates/compression-codecs/src/lib.rs
@@ -22,6 +22,8 @@ pub mod gzip;
 pub mod lz4;
 #[cfg(feature = "lzma")]
 pub mod lzma;
+#[cfg(feature = "ppmd")]
+pub mod ppmd;
 #[cfg(feature = "xz")]
 pub mod xz;
 #[cfg(feature = "lzma")]
@@ -49,6 +51,8 @@ pub use self::gzip::{GzipDecoder, GzipEncoder};
 pub use self::lz4::{Lz4Decoder, Lz4Encoder};
 #[cfg(feature = "lzma")]
 pub use self::lzma::{LzmaDecoder, LzmaEncoder};
+#[cfg(feature = "ppmd")]
+pub use self::ppmd::{PpmdDecoder, PpmdEncoder};
 #[cfg(feature = "xz")]
 pub use self::xz::{XzDecoder, XzEncoder};
 #[cfg(feature = "lzma")]
diff --git a/crates/compression-codecs/src/ppmd/decoder.rs b/crates/compression-codecs/src/ppmd/decoder.rs
new file mode 100644
index 00000000..0f9aff61
--- /dev/null
+++ b/crates/compression-codecs/src/ppmd/decoder.rs
@@ -0,0 +1,68 @@
+use crate::{DecodeV2, DecodedSize};
+use compression_core::util::{PartialBuffer, WriteBuffer};
+use std::io;
+
+use super::params::PpmdDecoderParams;
+
+#[derive(Default)]
+pub struct PpmdDecoder {
+    order: u32,
+    memory_size: u32,
+}
+
+impl PpmdDecoder {
+    pub fn with_params(params: PpmdDecoderParams) -> Self {
+        Self {
+            order: params.order,
+            memory_size: params.memory_size,
+        }
+    }
+
+    pub fn default_params() -> PpmdDecoderParams {
+        PpmdDecoderParams {
+            order: 8,
+            memory_size: 4 << 20,
+        }
+    }
+
+    pub fn new() -> Self {
+        Self::with_params(Self::default_params())
+    }
+}
+
+impl std::fmt::Debug for PpmdDecoder {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("PpmdDecoder")
+            .field("order", &self.order)
+            .field("memory_size", &self.memory_size)
+            .finish()
+    }
+}
+
+impl DecodeV2 for PpmdDecoder {
+    fn reinit(&mut self) -> io::Result<()> {
+        todo!()
+    }
+
+    fn decode(
+        &mut self,
+        _input: &mut PartialBuffer<&[u8]>,
+        _output: &mut WriteBuffer<'_>,
+    ) -> io::Result<bool> {
+        todo!()
+    }
+
+    fn flush(&mut self, _output: &mut WriteBuffer<'_>) -> io::Result<bool> {
+        todo!()
+    }
+
+    fn finish(&mut self, _output: &mut WriteBuffer<'_>) -> io::Result<bool> {
+        todo!()
+    }
+}
+
+impl DecodedSize for PpmdDecoder {
+    fn decoded_size(_input: &[u8]) -> io::Result<u64> {
+        todo!()
+    }
+}
diff --git a/crates/compression-codecs/src/ppmd/encoder.rs b/crates/compression-codecs/src/ppmd/encoder.rs
new file mode 100644
index 00000000..898ba537
--- /dev/null
+++ b/crates/compression-codecs/src/ppmd/encoder.rs
@@ -0,0 +1,40 @@
+use crate::EncodeV2;
+use compression_core::util::{PartialBuffer, WriteBuffer};
+use std::io;
+
+use super::params::PpmdEncoderParams;
+
+#[derive(Debug)]
+pub struct PpmdEncoder {
+    order: u32,
+    memory_size: u32,
+    end_marker: bool,
+}
+
+impl PpmdEncoder {
+    pub fn from_params(params: PpmdEncoderParams) -> Self {
+        Self {
+            order: params.order,
+            memory_size: params.memory_size,
+            end_marker: params.end_marker,
+        }
+    }
+}
+
+impl EncodeV2 for PpmdEncoder {
+    fn encode(
+        &mut self,
+        _input: &mut PartialBuffer<&[u8]>,
+        _output: &mut WriteBuffer<'_>,
+    ) -> io::Result<()> {
+        todo!()
+    }
+
+    fn flush(&mut self, _output: &mut WriteBuffer<'_>) -> io::Result<bool> {
+        todo!()
+    }
+
+    fn finish(&mut self, _output: &mut WriteBuffer<'_>) -> io::Result<bool> {
+        todo!()
+    }
+}
diff --git a/crates/compression-codecs/src/ppmd/mod.rs b/crates/compression-codecs/src/ppmd/mod.rs
new file mode 100644
index 00000000..c06e973d
--- /dev/null
+++ b/crates/compression-codecs/src/ppmd/mod.rs
@@ -0,0 +1,14 @@
+use compression_core::Level;
+
+mod decoder;
+mod encoder;
+pub mod params;
+
+pub use decoder::PpmdDecoder;
+pub use encoder::PpmdEncoder;
+
+impl PpmdEncoder {
+    pub fn new(level: Level) -> Self {
+        Self::from_params(params::PpmdEncoderParams::from(level))
+    }
+}
diff --git a/crates/compression-codecs/src/ppmd/params.rs b/crates/compression-codecs/src/ppmd/params.rs
new file mode 100644
index 00000000..380874b0
--- /dev/null
+++ b/crates/compression-codecs/src/ppmd/params.rs
@@ -0,0 +1,20 @@
+use compression_core::Level;
+
+#[derive(Debug, Clone, Copy)]
+pub struct PpmdEncoderParams {
+    pub order: u32,
+    pub memory_size: u32,
+    pub end_marker: bool,
+}
+
+#[derive(Debug, Clone, Copy)]
+pub struct PpmdDecoderParams {
+    pub order: u32,
+    pub memory_size: u32,
+}
+
+impl From<Level> for PpmdEncoderParams {
+    fn from(_value: Level) -> Self {
+        todo!()
+    }
+}
diff --git a/deny.toml b/deny.toml
index dc727e4d..8c2d62c3 100644
--- a/deny.toml
+++ b/deny.toml
@@ -9,6 +9,7 @@ allow = [
   "BSD-3-Clause",
   "Unicode-3.0",
   "bzip2-1.0.6",
+  "CC0-1.0",
 ]
 
 [bans]