diff --git a/code/factor/.gitignore b/code/factor/.gitignore
new file mode 100644
index 0000000..0d9689f
--- /dev/null
+++ b/code/factor/.gitignore
@@ -0,0 +1,2 @@
+bbhw/bbhw
+factor
diff --git a/code/factor/README.md b/code/factor/README.md
new file mode 100644
index 0000000..024c2ac
--- /dev/null
+++ b/code/factor/README.md
@@ -0,0 +1,27 @@
+# Factor
+
+From [Factor's homepage]:
+
+> The Factor programming language is a concatenative,
+> stack-based programming language with high-level features including dynamic types,
+> extensible syntax, macros, and garbage collection.
+> On a practical side, Factor has a full-featured library,
+> supports many different platforms, and has been extensively documented.
+>
+> The implementation is fully compiled for performance,
+> while still supporting interactive development.
+> Factor applications are portable between all common platforms.
+> Factor can deploy stand-alone applications on all platforms.
+> Full source code for the Factor project is available under a BSD license.
+
+---
+
+If Factor is already installed and its `factor` in your path,
+`run` will use the fast, non-optimizing compiler to run `bbhw.factor`,
+and `run-optimized` will use the slow, optimizing compiler to build `bbhw`
+from `bbhw.factor` and run that.
+
+If Factor is not found,
+either of those scripts will first download and build Factor itself.
+
+[Factor's homepage]: https://factorcode.org/
diff --git a/code/factor/bbhw/bbhw.factor b/code/factor/bbhw/bbhw.factor
new file mode 100644
index 0000000..5dd592d
--- /dev/null
+++ b/code/factor/bbhw/bbhw.factor
@@ -0,0 +1,34 @@
+USING: calendar combinators.short-circuit.smart command-line
+interpolate io kernel math math.parser namespaces ranges
+sequences threads ;
+IN: bbhw
+
+: ask-n ( -- str )
+  "countdown: " write flush
+  readln ;
+
+: initial-n ( -- str )
+  command-line get
+  [ ask-n ] [ first ] if-empty ;
+
+: valid-n? ( str -- ? )
+  string>number
+  { [ ] [ integer? ] [ 0 > ] } && ;
+
+: say-bye-bye ( n -- )
+  "World, Hello..." write
+  1 [a..b] [
+    I"${}..." write flush
+    1 seconds sleep
+  ] each
+  "Bye Bye." print ;
+
+: main ( -- )
+  initial-n
+  [ dup valid-n? ] [
+    I"Invalid countdown ${}, try again..." print
+    ask-n
+  ] until
+  string>number say-bye-bye ;
+
+MAIN: main
diff --git a/code/factor/run b/code/factor/run
new file mode 100755
index 0000000..4b1d2b8
--- /dev/null
+++ b/code/factor/run
@@ -0,0 +1,29 @@
+#!/bin/sh -e
+PATH_HERE=$(pwd)/$(dirname "$0")
+
+FACTOR=$(which factor)
+# This is usually an irrelevant prime factors tool that we ignore:
+if [ -x "$FACTOR" ]; then
+  if $FACTOR --help 2>&1 | grep -q 'prime factors'; then
+    FACTOR=""
+  fi
+fi
+
+# If not found, build Factor from source:
+if [ "$FACTOR" = "" ]; then
+  PATH_REPO="$PATH_HERE/factor"
+  FACTOR="$PATH_REPO/factor"
+
+  if [ ! -x "$FACTOR" ]; then
+    if [ ! -d "$PATH_REPO" ]; then
+      git clone -v --depth=1 git@github.com:factor/factor
+    fi
+    cd "$PATH_REPO"
+    git checkout master
+    git pull
+    ./build.sh net-bootstrap
+  fi
+fi
+
+# Use the fast, non-optimizing compiler to run bbhw:
+$FACTOR "$PATH_HERE/bbhw/bbhw.factor" "$@"
diff --git a/code/factor/run-optimized b/code/factor/run-optimized
new file mode 100755
index 0000000..a1adf9d
--- /dev/null
+++ b/code/factor/run-optimized
@@ -0,0 +1,36 @@
+#!/bin/sh -e
+PATH_HERE=$(pwd)/$(dirname "$0")
+
+FACTOR=$(which factor)
+# This is usually an irrelevant prime factors tool that we ignore:
+if [ -x "$FACTOR" ]; then
+  if $FACTOR --help 2>&1 | grep -q 'prime factors'; then
+    FACTOR=""
+  fi
+fi
+
+# If not found, build Factor from source:
+if [ "$FACTOR" = "" ]; then
+  PATH_REPO="$PATH_HERE/factor"
+  FACTOR="$PATH_REPO/factor"
+
+  if [ ! -x "$FACTOR" ]; then
+    if [ ! -d "$PATH_REPO" ]; then
+      git clone -v --depth=1 git@github.com:factor/factor
+    fi
+    cd "$PATH_REPO"
+    git checkout master
+    git pull
+    ./build.sh net-bootstrap
+  fi
+fi
+
+# Use the slow, optimizing compiler to build bbhw:
+BIN="$PATH_HERE"/bbhw/bbhw
+if [ ! -x "$BIN" ]; then
+  $FACTOR -roots="$PATH_HERE" -e='"bbhw" deploy'
+  mv "$($FACTOR -e='deploy-directory get absolute-path print')/bbhw/bbhw" "$BIN"
+fi
+
+# Run it:
+$BIN "$@"