diff --git a/ch14/add/Cargo.lock b/ch14/add/Cargo.lock
new file mode 100644
index 0000000..96a804b
--- /dev/null
+++ b/ch14/add/Cargo.lock
@@ -0,0 +1,140 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "add_one"
+version = "0.1.0"
+dependencies = [
+ "rand",
+]
+
+[[package]]
+name = "adder"
+version = "0.1.0"
+dependencies = [
+ "add_one",
+]
+
+[[package]]
+name = "cfg-if"
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+checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
+
+[[package]]
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+checksum = "c4567c8db10ae91089c99af84c68c38da3ec2f087c3f82960bcdbf3656b6f4d7"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.171"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c19937216e9d3aa9956d9bb8dfc0b0c8beb6058fc4f7a4dc4d850edf86a237d6"
+
+[[package]]
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+checksum = "85eae3c4ed2f50dcfe72643da4befc30deadb458a9b590d720cde2f2b1e97da9"
+dependencies = [
+ "zerocopy",
+]
+
+[[package]]
+name = "proc-macro2"
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+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
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+checksum = "1885c039570dc00dcb4ff087a89e185fd56bae234ddc7f056a945bf36467248d"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "rand"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
+dependencies = [
+ "libc",
+ "rand_chacha",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_chacha"
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+source = "registry+https://github.com/rust-lang/crates.io-index"
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+dependencies = [
+ "ppv-lite86",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
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+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
+dependencies = [
+ "getrandom",
+]
+
+[[package]]
+name = "syn"
+version = "2.0.100"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b09a44accad81e1ba1cd74a32461ba89dee89095ba17b32f5d03683b1b1fc2a0"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a5f39404a5da50712a4c1eecf25e90dd62b613502b7e925fd4e4d19b5c96512"
+
+[[package]]
+name = "wasi"
+version = "0.11.0+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
+
+[[package]]
+name = "zerocopy"
+version = "0.8.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2586fea28e186957ef732a5f8b3be2da217d65c5969d4b1e17f973ebbe876879"
+dependencies = [
+ "zerocopy-derive",
+]
+
+[[package]]
+name = "zerocopy-derive"
+version = "0.8.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a996a8f63c5c4448cd959ac1bab0aaa3306ccfd060472f85943ee0750f0169be"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
diff --git a/ch14/add/Cargo.toml b/ch14/add/Cargo.toml
new file mode 100644
index 0000000..3da84b9
--- /dev/null
+++ b/ch14/add/Cargo.toml
@@ -0,0 +1,6 @@
+[workspace]
+
+members = [
+  "adder",
+  "add_one",
+]
diff --git a/ch14/add/add_one/Cargo.toml b/ch14/add/add_one/Cargo.toml
new file mode 100644
index 0000000..bc758bd
--- /dev/null
+++ b/ch14/add/add_one/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "add_one"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+rand = "0.8.5"
diff --git a/ch14/add/add_one/src/lib.rs b/ch14/add/add_one/src/lib.rs
new file mode 100644
index 0000000..9524fe1
--- /dev/null
+++ b/ch14/add/add_one/src/lib.rs
@@ -0,0 +1,21 @@
+use rand;
+
+pub fn add(left: u64, right: u64) -> u64 {
+    left + right
+}
+
+pub fn add_one(x: i32) -> i32 {
+    x + 1
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn it_works() {
+        // let result = add(2, 2);
+        // assert_eq!(result, 4);
+        assert_eq!(3, add_one(2));
+    }
+}
diff --git a/ch14/add/adder/Cargo.toml b/ch14/add/adder/Cargo.toml
new file mode 100644
index 0000000..55c0203
--- /dev/null
+++ b/ch14/add/adder/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "adder"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+add_one = { path = "../add_one" }
diff --git a/ch14/add/adder/src/main.rs b/ch14/add/adder/src/main.rs
new file mode 100644
index 0000000..1316294
--- /dev/null
+++ b/ch14/add/adder/src/main.rs
@@ -0,0 +1,6 @@
+use add_one;
+
+fn main() {
+    let num = 10;
+    println!("Hello, world! {num} plus one is {}!", add_one::add_one(num));
+}
diff --git a/ch14/publishing-to-crates-io/Cargo.lock b/ch14/publishing-to-crates-io/Cargo.lock
new file mode 100644
index 0000000..930ccc1
--- /dev/null
+++ b/ch14/publishing-to-crates-io/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "publishing-to-crates-io"
+version = "0.1.0"
diff --git a/ch14/publishing-to-crates-io/Cargo.toml b/ch14/publishing-to-crates-io/Cargo.toml
new file mode 100644
index 0000000..f5060f0
--- /dev/null
+++ b/ch14/publishing-to-crates-io/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "publishing-to-crates-io"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
diff --git a/ch14/publishing-to-crates-io/src/lib.rs b/ch14/publishing-to-crates-io/src/lib.rs
new file mode 100644
index 0000000..750ce69
--- /dev/null
+++ b/ch14/publishing-to-crates-io/src/lib.rs
@@ -0,0 +1,48 @@
+//! # Art
+//!
+//! A library for modeling artistic concepts
+
+// These are re-exports
+pub use self::kinds::PrimaryColor;
+pub use self::kinds::SecondaryColor;
+pub use self::utils::mix;
+
+pub mod kinds {
+    pub enum PrimaryColor {
+        Red,
+        Yellow,
+        Blue,
+    }
+
+    pub enum SecondaryColor {
+        Orange,
+        Green,
+        Purple,
+    }
+}
+
+pub mod utils {
+    use crate::kinds::*;
+
+    /// Combines two primary colors in equal amounts to create
+    /// a secondary color
+    pub fn mix(c1: PrimaryColor, c2: PrimaryColor) -> SecondaryColor {
+        SecondaryColor::Orange
+        // unimplemented!()
+    }
+}
+
+pub fn add(left: u64, right: u64) -> u64 {
+    left + right
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn it_works() {
+        let result = add(2, 2);
+        assert_eq!(result, 4);
+    }
+}
diff --git a/ch14/publishing-to-crates-io/src/main.rs b/ch14/publishing-to-crates-io/src/main.rs
new file mode 100644
index 0000000..1f5cd4d
--- /dev/null
+++ b/ch14/publishing-to-crates-io/src/main.rs
@@ -0,0 +1,8 @@
+use publishing_to_crates_io::kinds::PrimaryColor;
+use publishing_to_crates_io::utils::mix;
+
+fn main() {
+    let red = PrimaryColor::Red;
+    let yellow = PrimaryColor::Yellow;
+    mix(red, yellow);
+}
diff --git a/ch14/release-profiles/Cargo.lock b/ch14/release-profiles/Cargo.lock
new file mode 100644
index 0000000..f6ce198
--- /dev/null
+++ b/ch14/release-profiles/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "release-profiles"
+version = "0.1.0"
diff --git a/ch14/release-profiles/Cargo.toml b/ch14/release-profiles/Cargo.toml
new file mode 100644
index 0000000..eb1c461
--- /dev/null
+++ b/ch14/release-profiles/Cargo.toml
@@ -0,0 +1,17 @@
+[package]
+name = "release-profiles"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+
+# Cargo has default settings for each of the profiles
+# for building in the `[profiles.*]` sections.
+# opt-level controls the amount of optimizations appied
+# at compile time.
+# 1 is not the default value
+[profile.dev]
+opt-level = 1
+
+[profile.release]
+opt-level = 3
diff --git a/ch14/release-profiles/src/lib.rs b/ch14/release-profiles/src/lib.rs
new file mode 100644
index 0000000..8ca0c6c
--- /dev/null
+++ b/ch14/release-profiles/src/lib.rs
@@ -0,0 +1,30 @@
+//!  # Release Profiles
+//!
+//! `release_profiles` is a collection of utilities to
+//! learn Rust.
+//!
+//! The doubles slashes and then ! adds documentation to
+//! the item that contains the comments rather than to the
+//! items following the comments. Typically used in crate root
+//! file.
+//!
+//! Documentation comments have three slashes which
+//! generate HTML.
+
+/// Adds one to the given number.
+/// This is literally markdown
+///
+/// # Examples
+///
+/// ```
+/// let arg = 5;
+/// let answer = release_profiles::add_one(arg);
+///
+/// assert_eq!(6, answer);
+/// ```
+pub fn add_one(x: i32) -> i32 {
+    x + 1
+}
+
+// Like the `# Examples` section above,
+// may also use `Panics`, `Errors`, or `Safety`
diff --git a/ch14/release-profiles/src/main.rs b/ch14/release-profiles/src/main.rs
new file mode 100644
index 0000000..e7a11a9
--- /dev/null
+++ b/ch14/release-profiles/src/main.rs
@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}