diff --git a/.github/workflows/reusable-testing.yml b/.github/workflows/reusable-testing.yml
index ef3ddab20..2dd8b0ece 100644
--- a/.github/workflows/reusable-testing.yml
+++ b/.github/workflows/reusable-testing.yml
@@ -21,11 +21,19 @@ on:
       use-phar:
         type: boolean
         required: true
+      os:
+        type: string
+        required: false
+        default: 'ubuntu-22.04'
+      mysql:
+        type: string
+        required: false
+        default: ''
 
 jobs:
   run-test:
-    name: WP ${{ inputs.wp }} | PHP ${{ inputs.php }} | ${{ inputs.dbtype == 'sqlite' && 'SQLite' || inputs.dbtype == 'mysql' && 'MySQL' || 'MariaDB' }}${{ inputs.use-phar && ' (Phar)' || '' }}${{ inputs.object_cache == 'sqlite' && ' (Obj Cache)' || '' }}
-    runs-on: ubuntu-22.04
+    name: WP ${{ inputs.wp }} | PHP ${{ inputs.php }} | ${{ inputs.dbtype == 'sqlite' && 'SQLite' || inputs.dbtype == 'mysql' && 'MySQL' || 'MariaDB' }}${{ inputs.use-phar && ' (Phar)' || '' }}${{ inputs.object_cache == 'sqlite' && ' (Obj Cache)' || '' }}${{ startsWith( inputs.os, 'windows' ) && ' (Windows)' || '' }}${{ startsWith( inputs.os, 'macos' ) && ' (macOS)' || '' }}
+    runs-on: ${{ inputs.os || 'ubuntu-22.04' }}
     continue-on-error: ${{ inputs.dbtype == 'sqlite' || inputs.object_cache == 'sqlite' }}
 
     env:
@@ -45,20 +53,29 @@ jobs:
 
       - name: Check existence of composer.json & behat.yml files
         id: check_files
+        shell: bash
         run: echo "files_exists=$([ -f composer.json ] && [ -f behat.yml ] && echo true || echo false)" >> "$GITHUB_OUTPUT"
 
       - name: Install Ghostscript
-        if: steps.check_files.outputs.files_exists == 'true'
+        if: steps.check_files.outputs.files_exists == 'true' && (inputs.os == 'ubuntu-22.04' || inputs.os == '')
         run: |
           sudo apt-get update
           sudo apt-get install ghostscript -y
 
+      - name: Install dependencies (Windows)
+        if: ${{ startsWith(inputs.os, 'windows') }}
+        run: choco install sqlite ghostscript --yes
+
+      - name: Install dependencies (macOS)
+        if: ${{ startsWith(inputs.os, 'macos') }}
+        run: brew install ghostscript
+
       - name: Set up PHP environment
         if: steps.check_files.outputs.files_exists == 'true'
         uses: shivammathur/setup-php@accd6127cb78bee3e8082180cb391013d204ef9f # v2
         with:
           php-version: '${{ inputs.php }}'
-          extensions: gd, imagick, mysql, zip, pdo_sqlite
+          extensions: gd, imagick, mysql, zip, pdo_sqlite, exif, fileinfo
           coverage: none
           tools: composer
 
@@ -69,7 +86,7 @@ jobs:
           COMPOSER_ROOT_VERSION: dev-${{ github.event.repository.default_branch }}
 
       - name: Change ImageMagick policy to allow pdf->png conversion.
-        if: steps.check_files.outputs.files_exists == 'true'
+        if: steps.check_files.outputs.files_exists == 'true' && (inputs.os == 'ubuntu-22.04' || inputs.os == '')
         run: |
           sudo sed -i 's/^.*policy.*coder.*none.*PDF.*//' /etc/ImageMagick-6/policy.xml
 
@@ -78,13 +95,19 @@ jobs:
         if: ${{ inputs.dbtype != 'sqlite' }}
         uses: shogo82148/actions-setup-mysql@9c42ca180d5f1dd4dceb54c23c5eda0384f4d265 # v1
         with:
-          mysql-version: '8.0' # Standard MySQL version for these tests
+          mysql-version: ${{ inputs.mysql || '8.0' }}
           auto-start: true
           root-password: ${{ env.WP_CLI_TEST_DBROOTPASS }}
           user: ${{ env.WP_CLI_TEST_DBUSER}}
           password: ${{ env.WP_CLI_TEST_DBPASS}}
           my-cnf: |
             default_authentication_plugin=mysql_native_password
+            ${{ inputs.dbtype == 'mariadb' && '[client]' || '' }}
+            ${{ inputs.dbtype == 'mariadb' && 'disable-ssl-verify-server-cert' || '' }}
+
+      - name: Remove system MySQL binary
+        if: steps.check_files.outputs.files_exists == 'true' && inputs.dbtype != 'sqlite'
+        run: sudo rm -f /usr/bin/mysql /usr/bin/mysqldump
 
       - name: Prepare test database
         if: steps.check_files.outputs.files_exists == 'true' && inputs.dbtype != 'sqlite'
@@ -92,6 +115,7 @@ jobs:
 
       - name: Conditionally use Phar instead of source
         if: steps.check_files.outputs.files_exists == 'true' && inputs.use-phar == true
+        shell: bash
         run: echo "TEST_PHAR=nightly" >> $GITHUB_ENV
 
       - name: Check Behat environment
@@ -100,7 +124,10 @@ jobs:
           WP_VERSION: '${{ inputs.wp }}'
           WP_CLI_TEST_DBTYPE: ${{ inputs.dbtype }}
           WP_CLI_TEST_DBSOCKET: '${{ steps.setup-mysql.outputs.base-dir }}/tmp/mysql.sock'
-        run: WP_CLI_TEST_DEBUG_BEHAT_ENV=1 composer behat
+          WP_CLI_TEST_DEBUG_BEHAT_ENV: 1
+          SSL_CERT_FILE: '${{ steps.setup-mysql.outputs.base-dir }}/var/ca.pem'
+          CURL_CA_BUNDLE: /etc/ssl/certs/ca-certificates.crt
+        run: composer behat
 
       - name: Run Behat
         if: steps.check_files.outputs.files_exists == 'true'
@@ -109,4 +136,6 @@ jobs:
           WP_CLI_TEST_DBTYPE: ${{ inputs.dbtype }}
           TEST_PACKAGE: 'wp-cli/${{ inputs.test-package }}'
           WP_CLI_TEST_DBSOCKET: '${{ steps.setup-mysql.outputs.base-dir }}/tmp/mysql.sock'
+          SSL_CERT_FILE: '${{ steps.setup-mysql.outputs.base-dir }}/var/ca.pem'
+          CURL_CA_BUNDLE: /etc/ssl/certs/ca-certificates.crt
         run: composer test
diff --git a/.github/workflows/testing.yml b/.github/workflows/testing.yml
index 141287617..9ef4b99c4 100644
--- a/.github/workflows/testing.yml
+++ b/.github/workflows/testing.yml
@@ -19,9 +19,10 @@ jobs:
       matrix:
         php: ['7.2', '8.5']
         wp: ['latest', 'trunk']
-        dbtype: ['mysql', 'sqlite']
+        dbtype: ['mysql', 'sqlite', 'mariadb']
         object_cache: ['none', 'sqlite']
         use-phar: [false, true]
+        os: ['ubuntu-22.04', 'macos-latest', 'windows-latest']
         test-package:
           - wp-cli-bundle
           - wp-cli
@@ -59,9 +60,6 @@ jobs:
           - dbtype: mysql
             object_cache: sqlite
             
-          # SQLite runs only on WP latest and PHP 8.5
-          - dbtype: sqlite
-            wp: trunk
           - dbtype: sqlite
             php: '7.2'
             
@@ -78,11 +76,53 @@ jobs:
             wp: trunk
           - use-phar: false
             wp: latest
+          - use-phar: true
+            php: '7.2'
             
           # Limit ancient php on trunk
           - php: '7.2'
             wp: trunk
             
+          # Only run one macos combination: php: 8.5, wp: trunk, dbtype: sqlite, object_cache: none, use-phar: false
+          - os: macos-latest
+            php: '7.2'
+          - os: macos-latest
+            wp: latest
+          - os: macos-latest
+            dbtype: mysql
+          - os: macos-latest
+            object_cache: sqlite
+            
+          # Only run one windows combination: php: 8.5, wp: trunk, dbtype: sqlite, object_cache: none, use-phar: false
+          - os: windows-latest
+            php: '7.2'
+          - os: windows-latest
+            wp: latest
+          - os: windows-latest
+            dbtype: mysql
+          - os: windows-latest
+            object_cache: sqlite
+
+          # Skip Windows tests for db-command to to environment configuration issues with SQLite.
+          - os: windows-latest
+            test-package: db-command
+            
+          # Limit MariaDB runs to php: 8.5, wp: trunk, os: ubuntu-22.04, object_cache: none, use-phar: false
+          - dbtype: mariadb
+            php: '7.2'
+          - dbtype: mariadb
+            wp: latest
+          - dbtype: mariadb
+            os: macos-latest
+          - dbtype: mariadb
+            os: windows-latest
+          - dbtype: mariadb
+            object_cache: sqlite
+          - dbtype: mariadb
+            use-phar: true
+
+
+
     uses: ./.github/workflows/reusable-testing.yml
     with:
       test-package: ${{ matrix.test-package }}
@@ -91,4 +131,6 @@ jobs:
       dbtype: ${{ matrix.dbtype }}
       object_cache: ${{ matrix.object_cache }}
       use-phar: ${{ matrix.use-phar }}
+      os: ${{ matrix.os }}
+      mysql: ${{ matrix.dbtype == 'mariadb' && 'mariadb-10.11' || 'mysql-8.0' }}
 
diff --git a/bin/test-phar b/bin/test-phar
index 591a7a6dc..fe5518279 100755
--- a/bin/test-phar
+++ b/bin/test-phar
@@ -75,9 +75,9 @@ for RELEASE in $RELEASES; do
 
 	# Download binary and verify MD5 checksum.
 	BIN_FOLDER="$(mktemp -d)"
-	wget -O "${BIN_FOLDER}/wp-cli.phar.md5" "$MD5_URL"
+	curl -sLo "${BIN_FOLDER}/wp-cli.phar.md5" "$MD5_URL"
 	TARGET_MD5=$(cat "${BIN_FOLDER}/wp-cli.phar.md5")
-	wget -O "${BIN_FOLDER}/wp-cli.phar" "$PHAR_URL"
+	curl -sLo "${BIN_FOLDER}/wp-cli.phar" "$PHAR_URL"
 	if hash md5sum 2>/dev/null; then
 		DOWNLOAD_MD5=$(md5sum "${BIN_FOLDER}/wp-cli.phar" | cut -d ' ' -f 1)
 	else
diff --git a/bin/test-source b/bin/test-source
index 204690c94..b00d310cc 100755
--- a/bin/test-source
+++ b/bin/test-source
@@ -43,13 +43,15 @@ for REPO in $REPOS; do
 
 	echo "Testing package $REPO..."
 
-	BEHAT_TAGS=$(BEHAT_FEATURES_FOLDER=${BUILD_DIR}/vendor/${REPO}/features php ${BUILD_DIR}/vendor/wp-cli/wp-cli-tests/utils/behat-tags.php)
+	FEATURES_FOLDER="${BUILD_DIR}/vendor/${REPO}/features"
+
+	BEHAT_TAGS=$(BEHAT_FEATURES_FOLDER="$FEATURES_FOLDER" php "${BUILD_DIR}/vendor/wp-cli/wp-cli-tests/utils/behat-tags.php")
 	echo "Behat Tags: $BEHAT_TAGS"
 
 	set +e
-	"${BUILD_DIR}/vendor/bin/behat" --format progress $BEHAT_TAGS --strict  --suite $REPO
+	"${BUILD_DIR}/vendor/bin/behat" --format progress $BEHAT_TAGS --strict --suite $REPO
 	if [ $? -ne 0 ]; then
-		"${BUILD_DIR}/vendor/bin/behat" --format progress $BEHAT_TAGS --strict  --suite $REPO --rerun
+		"${BUILD_DIR}/vendor/bin/behat" --format progress $BEHAT_TAGS --strict --suite $REPO --rerun
 		if [ $? -ne 0 ]; then
 			FAILED_PACKAGES="$FAILED_PACKAGES ${RELEASE}:${REPO}"
 		fi