diff --git a/cranelift/src/libcretonne/lib.rs b/cranelift/src/libcretonne/lib.rs
index 248c6bb37f..8b92e5dbed 100644
--- a/cranelift/src/libcretonne/lib.rs
+++ b/cranelift/src/libcretonne/lib.rs
@@ -5,6 +5,8 @@
 //
 // ====------------------------------------------------------------------------------------==== //
 
+pub const VERSION: &'static str = env!("CARGO_PKG_VERSION");
+
 pub mod types;
 pub mod immediates;
 pub mod entities;
diff --git a/cranelift/src/tools/Cargo.lock b/cranelift/src/tools/Cargo.lock
index 91e9a5fae4..0b85735d6c 100644
--- a/cranelift/src/tools/Cargo.lock
+++ b/cranelift/src/tools/Cargo.lock
@@ -4,6 +4,16 @@ version = "0.0.0"
 dependencies = [
  "cretonne 0.0.0",
  "cretonne-reader 0.0.0",
+ "docopt 0.6.80 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "aho-corasick"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "memchr 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -17,3 +27,94 @@ dependencies = [
  "cretonne 0.0.0",
 ]
 
+[[package]]
+name = "docopt"
+version = "0.6.80"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "regex 0.1.71 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rustc-serialize 0.3.19 (registry+https://github.com/rust-lang/crates.io-index)",
+ "strsim 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "kernel32-sys"
+version = "0.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-build 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "memchr"
+version = "0.1.11"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "regex"
+version = "0.1.71"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "aho-corasick 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memchr 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex-syntax 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "thread_local 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "utf8-ranges 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "rustc-serialize"
+version = "0.3.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "strsim"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "thread-id"
+version = "2.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.11 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "thread_local"
+version = "0.2.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "thread-id 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "utf8-ranges"
+version = "0.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "winapi"
+version = "0.2.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "winapi-build"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
diff --git a/cranelift/src/tools/Cargo.toml b/cranelift/src/tools/Cargo.toml
index 702bd635e6..8059002f40 100644
--- a/cranelift/src/tools/Cargo.toml
+++ b/cranelift/src/tools/Cargo.toml
@@ -12,3 +12,5 @@ path = "main.rs"
 [dependencies]
 cretonne = { path = "../libcretonne" }
 cretonne-reader = { path = "../libreader" }
+docopt = "0.6.80"
+rustc-serialize = "0.3.19"
diff --git a/cranelift/src/tools/cat.rs b/cranelift/src/tools/cat.rs
new file mode 100644
index 0000000000..c8f30d0a99
--- /dev/null
+++ b/cranelift/src/tools/cat.rs
@@ -0,0 +1,28 @@
+//! The `cat` sub-command.
+//!
+//! Read a sequence of Cretonne IL files and print them again to stdout. This has the effect of
+//! normalizing formatting and removing comments.
+
+use CommandResult;
+use std::fs::File;
+use std::io::Read;
+
+pub fn run(files: Vec<String>) -> CommandResult {
+    for (i, f) in files.into_iter().enumerate() {
+        if i != 0 {
+            println!("");
+        }
+        try!(cat_one(f))
+    }
+    Ok(())
+}
+
+fn cat_one(filename: String) -> CommandResult {
+    let mut file = try!(File::open(&filename).map_err(|e| format!("{}: {}", filename, e)));
+    let mut buffer = String::new();
+    try!(file.read_to_string(&mut buffer)
+        .map_err(|e| format!("Couldn't read {}: {}", filename, e)));
+
+    print!("{}", buffer);
+    Ok(())
+}
diff --git a/cranelift/src/tools/main.rs b/cranelift/src/tools/main.rs
index 97b261d22d..1ea40c201c 100644
--- a/cranelift/src/tools/main.rs
+++ b/cranelift/src/tools/main.rs
@@ -1,5 +1,65 @@
 
 extern crate cretonne;
 extern crate cton_reader;
+extern crate docopt;
+extern crate rustc_serialize;
 
-fn main() {}
+use cretonne::VERSION;
+use docopt::Docopt;
+use std::io::{self, Write};
+use std::process;
+
+
+mod cat;
+
+const USAGE: &'static str = "
+Cretonne code generator utility
+
+Usage:
+    cton-util cat <file>...
+    cton-util --help | --version
+
+Options:
+    -h, --help  print this help message
+    --version   print the Cretonne version
+
+";
+
+#[derive(RustcDecodable, Debug)]
+struct Args {
+    cmd_cat: bool,
+    arg_file: Vec<String>,
+}
+
+/// A command either succeeds or fails with an error message.
+pub type CommandResult = Result<(), String>;
+
+/// Parse the command line arguments and run the requested command.
+fn cton_util() -> CommandResult {
+    // Parse comand line arguments.
+    let args: Args = Docopt::new(USAGE)
+        .and_then(|d| {
+            d.help(true)
+                .version(Some(format!("Cretonne {}", VERSION)))
+                .decode()
+        })
+        .unwrap_or_else(|e| e.exit());
+
+    // Find the sub-command to execute.
+    if args.cmd_cat {
+        cat::run(args.arg_file)
+    } else {
+        // Debugging / shouldn't happen with proper command line handling above.
+        Err(format!("Unhandled args: {:?}", args))
+    }
+}
+
+fn main() {
+    if let Err(mut msg) = cton_util() {
+        if !msg.ends_with('\n') {
+            msg.push('\n');
+        }
+        io::stderr().write(msg.as_bytes()).unwrap();
+        process::exit(1);
+    }
+}