diff --git a/lib/compare_semver b/lib/compare_semver
new file mode 100755
index 0000000..d4cbf13
--- /dev/null
+++ b/lib/compare_semver
@@ -0,0 +1,142 @@
+#!/bin/bash
+
+set -euo pipefail
+
+# Validate a semver string, exit if invalid.
+# Arguments:
+#   $1: semver string to validate
+validate_semver() {
+
+  # Regex for a semver digit
+  D='0|[1-9][0-9]*'
+  # Regex for a semver pre-release word
+  PW='[0-9]*[a-zA-Z-][0-9a-zA-Z-]*'
+  # Regex for a semver build-metadata word
+  MW='[0-9a-zA-Z-]+'
+
+  # Regex pattern to match a semver string with numeric version identifiers, pre-release identifiers, and build metadata
+  semver_pattern="^($D)\.($D)\.($D)(-(($D|$PW)(\.($D|$PW))*))?(\+($MW(\.$MW)*))?$"
+
+  if ! [[ $1 =~ $semver_pattern ]]; then
+    echo "$0: Invalid semver string: $1" >&2
+    echo "$0: Expected format 'x.y.z' or 'x.y.z-pre-release'."
+    exit 1
+  fi
+}
+
+# Function to compare two component strings.
+# Arguments:
+#   $1: First component string
+#   $2: Second component string
+# Output:
+#   -1 if the first component has lower precedence
+#    1 if the first component has higher precedence
+compare_components() {
+  if (($1 > $2)); then
+    echo 1 && exit 0
+  elif (($1 < $2)); then
+    echo -1 && exit 0
+  fi
+}
+
+# Function to compare pre-release identifiers.
+# Arguments:
+#   $1: First pre-release identifier
+#   $2: Second pre-release identifier
+# Output:
+#   -1 if the first pre-release identifier has lower precedence
+#    0 if both identifiers are equal
+#    1 if the first pre-release identifier has higher precedence
+compare_prerelease() {
+  # If both pre-release identifiers are empty, they are considered equal
+  if [ -z "$1" ] && [ -z "$2" ]; then
+    echo 0 && exit 0
+  fi
+
+  # If one of the pre-release identifiers is empty, the one with the non-empty identifier has lower precedence
+  if [ -z "$1" ]; then
+    echo 1 && exit 0
+  elif [ -z "$2" ]; then
+    echo -1 && exit 0
+  fi
+
+  # Split pre-release identifiers into individual parts
+  IFS='.' read -r -a parts1 <<<"$1"
+  IFS='.' read -r -a parts2 <<<"$2"
+
+  # Compare each part of the pre-release identifiers
+  for ((i = 0; i < ${#parts1[@]} || i < ${#parts2[@]}; i++)); do
+    part1="${parts1[i]:=""}"
+    part2="${parts2[i]:=""}"
+
+    # If one part is missing, it has lower precedence
+    if [ -z "$part1" ]; then
+      echo -1 && exit 0
+    elif [ -z "$part2" ]; then
+      echo 1 && exit 0
+    fi
+
+    # If parts are numeric, compare numerically
+    if [[ "$part1" =~ ^[0-9]+$ ]] && [[ "$part2" =~ ^[0-9]+$ ]]; then
+      compare_components "$part1" "$part2"
+    fi
+
+    # Lexicographically compare non-numeric parts
+    [[ "$part1" < "$part2" ]] && echo -1 && exit 0
+    [[ "$part1" > "$part2" ]] && echo 1 && exit 0
+  done
+
+  # Versions are equal
+  echo 0
+}
+
+# Function to compare two semver strings.
+# Arguments:
+#   $1: First semver string
+#   $2: Second semver string
+# Output:
+#   -1 if the first version is less than the second version
+#    0 if the versions are equal
+#    1 if the first version is greater than the second version
+compare_semver() {
+  # Validate the semver strings
+  validate_semver "$1"
+  validate_semver "$2"
+
+  # Remove build metadata if present
+  semver1=$(cut -d+ -f1 <<<"$1")
+  semver2=$(cut -d+ -f1 <<<"$2")
+
+  # Extract major, minor, patch, and pre-release versions from the input strings
+  major1=$(cut -d. -f1 <<<"$semver1")
+  minor1=$(cut -d. -f2 <<<"$semver1")
+  patch1=$(cut -d. -f3 -s <<<"$semver1" | cut -d- -f1)
+  prerelease1=$(cut -d- -f2- -s <<<"$semver1")
+
+  major2=$(cut -d. -f1 <<<"$semver2")
+  minor2=$(cut -d. -f2 <<<"$semver2")
+  patch2=$(cut -d. -f3 -s <<<"$semver2" | cut -d- -f1)
+  prerelease2=$(cut -d- -f2- -s <<<"$semver2")
+
+  # Compare each component of the versions
+  compare_components "$major1" "$major2"
+  compare_components "$minor1" "$minor2"
+  compare_components "$patch1" "$patch2"
+
+  # Check if one version has a pre-release identifier while the other does not
+  if [ -n "$prerelease1" ] && [ -z "$prerelease2" ]; then
+    echo -1 && exit 0
+  elif [ -z "$prerelease1" ] && [ -n "$prerelease2" ]; then
+    echo 1 && exit 0
+  fi
+
+  # Compare pre-release identifiers if they exist
+  if [ -n "$prerelease1" ] && [ -n "$prerelease2" ]; then
+    compare_prerelease "$prerelease1" "$prerelease2" && exit 0
+  fi
+
+  # Versions are equal
+  echo 0
+}
+
+compare_semver "$1" "$2"
diff --git a/lib/test_compare_semver b/lib/test_compare_semver
new file mode 100755
index 0000000..837c0fb
--- /dev/null
+++ b/lib/test_compare_semver
@@ -0,0 +1,67 @@
+#!/bin/bash
+
+test_cases=(
+  # Versions are equal
+  "1.0.0 1.0.0 0"
+  "1.1.0 1.1.0 0"
+  "1.0.1 1.0.1 0"
+  "1.0.0-alpha 1.0.0-alpha 0"
+  "1.0.0-alpha.beta 1.0.0-alpha.beta 0"
+  "1.0.0-abc123.1.1.1 1.0.0-abc123.1.1.1 0"
+
+  # First version is less than second version
+  "1.0.0 2.0.0 -1"
+  "1.0.0 1.1.0 -1"
+  "1.0.0 1.0.1 -1"
+  "1.0.0-alpha 1.0.0 -1"
+
+  # First version is greater than second version
+  "2.0.0 1.0.0 1"
+  "1.1.0 1.0.0 1"
+  "1.0.1 1.0.0 1"
+  "1.0.0 1.0.0-alpha 1"
+  "1.0.0-alpha.1 1.0.0-alpha 1"
+
+  # Pre-release versions comparison
+  "1.0.0-alpha 1.0.0-alpha.beta -1"
+  "1.0.0-alpha.beta 1.0.0-beta -1"
+  "1.0.0-alpha.beta 1.0.0-beta.2 -1"
+  "1.0.0-alpha.beta 1.0.0-beta.11 -1"
+  "1.0.0-alpha.beta 1.0.0-rc.1 -1"
+  "1.0.0-alpha.beta 1.0.0 -1"
+  "1.0.0-beta 1.0.0-beta.2 -1"
+  "1.0.0-beta 1.0.0-beta.11 -1"
+  "1.0.0-beta 1.0.0-rc.1 -1"
+  "1.0.0-beta 1.0.0 -1"
+  "1.0.0-beta.2 1.0.0-beta.11 -1"
+  "1.0.0-beta.2 1.0.0-rc.1 -1"
+  "1.0.0-beta.2 1.0.0 -1"
+  "1.0.0-beta.11 1.0.0-rc.1 -1"
+  "1.0.0-rc.1 1.0.0-rc.2 -1"
+  "1.0.0-rc.1 1.0.0 -1"
+
+  # Versions with build metadata
+  "1.0.0 1.0.0+build.1 0"
+  "1.0.0 1.0.0+build.2 0"
+  "1.0.0-alpha 1.0.0-alpha+build.1 0"
+  "1.0.0-alpha+build.1 1.0.0-alpha+build.2 0"
+  "1.0.0-alpha+build.1 1.0.0+build.1 -1"
+  "1.0.0+early 1.0.1+late -1"
+  "1.0.0+early 1.1.0+late -1"
+  "1.0.0+early 2.0.0+late -1"
+)
+
+LIB="$(dirname "$(readlink -f "$0")")"
+
+# Run test cases
+for test_case in "${test_cases[@]}"; do
+  versions=()
+  read -ra versions <<<"$test_case"
+  result=$("$LIB/compare_semver" "${versions[0]}" "${versions[1]}")
+  expected="${versions[2]}"
+  if [ "$result" -eq "$expected" ]; then
+    echo "OK: ${versions[0]} compared to ${versions[1]} :: Result - $result"
+  else
+    echo "FAIL: ${versions[0]} compared to ${versions[1]} :: Expected - $expected, Actual - $result"
+  fi
+done
diff --git a/lib/utils.bash b/lib/utils.bash
index 24a1202..35eb1c0 100644
--- a/lib/utils.bash
+++ b/lib/utils.bash
@@ -6,9 +6,10 @@ REPO="smithy-lang/smithy"
 GH_REPO="https://github.com/$REPO"
 GH_REPO_API="https://api.github.com/repos/$REPO"
 TOOL_NAME="smithy"
+LIB="$(dirname "$(dirname "$(readlink -f "$0")")")/lib"
 
 fail() {
-  echo -e "asdf-$TOOL_NAME: $*"
+  printf '%s\n' "asdf-$TOOL_NAME: $*" >&2
   exit 1
 }
 
@@ -44,6 +45,11 @@ get_platform() {
 # get architecture, output it, quit if unsupported
 get_arch() {
   arch="$(uname -m)"
+  if [[ "$arch" =~ "arm64" ]]; then
+    # uname may return arm64 for arm-based machines, they're synonymous
+    arch="aarch64"
+  fi
+
   if [[ ! $(check_arch "$arch") ]]; then
     fail "unsupported architecture ($arch)"
   fi
@@ -59,7 +65,7 @@ check_arch() {
 }
 
 # get the url for the artifact to download, based on
-# the system (1st arg) and the version (2nd arg)
+# the system (1st arg), the version (2nd arg), and the file extensions (3rd arg)
 get_artifact_url() {
   check jq
   if [ "$#" -gt 1 ]; then
@@ -70,7 +76,7 @@ get_artifact_url() {
     else
       tag=$2
     fi
-    echo "$GH_REPO/releases/download/$tag/smithy-cli-$1.tar.gz"
+    echo "$GH_REPO/releases/download/$tag/smithy-cli-$1.$3"
   else
     fail "platform or version were not specified."
   fi
@@ -86,12 +92,37 @@ download_release() {
 
   if [ "$type" = "version" ]; then
     echo "* Downloading $TOOL_NAME release ($version)..."
-    url=$(get_artifact_url "$(get_platform)-$(get_arch)" "$version")
-    if [ "$url" ]; then
-      curl "${curl_opts[@]}" "$url" | tar xzf - -C "$path" ||
-        fail "Request to '$url' returned bad response ($?)."
+    platform=$(get_platform)
+    arch=$(get_arch)
+    # Based on the version, install from tar or zip
+    # versions earlier than 1.47.0 must install from tarball
+    vercmp="$(. "$LIB"/compare_semver "$version" "1.47.0")"
+    if [ "$vercmp" = "-1" ]; then
+      # version is less than 1.47.0, use tar
+      url=$(get_artifact_url "$(get_platform)-$(get_arch)" "$version" "tar.gz")
+      if [ "$url" ]; then
+        echo "Retrieving release at $url..."
+        curl "${curl_opts[@]}" "$url" | tar xzf - -C "$path" ||
+          fail "Request to '$url' returned bad response ($?)."
+      else
+        fail "Could not form url."
+      fi
     else
-      fail "Could not form url."
+      # version is greater than or equal to 1.47.0, use zip
+      url=$(get_artifact_url "$platform-$arch" "$version" "zip")
+      if [ "$url" ]; then
+        mkdir -p "$path"
+        echo "Retrieving release at $url..."
+        tmp_download_dir=$(mktemp -d -t asdf_extract_XXXXXXX)
+        cd "$tmp_download_dir"
+        curl "${curl_opts[@]}" -o smithy.zip "$url" || fail "Request to '$url' returned bad response ($?)."
+        unzip -oq smithy.zip
+        mv smithy-cli-"$platform"-"$arch"/* "$path"
+        rm -rf smithy-cli-"$platform"-"$arch" smithy.zip
+        cd -
+      else
+        fail "Could not form url."
+      fi
     fi
   else
     fail "Download by '$type' is not supported."
@@ -117,6 +148,8 @@ install_version() {
 
   (
     mkdir -p "$path"
+    # zips don't maintain permissions, so we need to add x perms to the right files
+    chmod +x "$download_path"/bin/* "$download_path"/lib/jspawnhelper
     cp -r "$download_path"/* "$path"
 
     # assert smithy exists and runs