diff --git a/src/__phutil_library_map__.php b/src/__phutil_library_map__.php
--- a/src/__phutil_library_map__.php
+++ b/src/__phutil_library_map__.php
@@ -471,7 +471,7 @@
     'ArcanistVariableReferenceSpacingXHPASTLinterRuleTestCase' => 'lint/linter/xhpast/rules/__tests__/ArcanistVariableReferenceSpacingXHPASTLinterRuleTestCase.php',
     'ArcanistVariableVariableXHPASTLinterRule' => 'lint/linter/xhpast/rules/ArcanistVariableVariableXHPASTLinterRule.php',
     'ArcanistVariableVariableXHPASTLinterRuleTestCase' => 'lint/linter/xhpast/rules/__tests__/ArcanistVariableVariableXHPASTLinterRuleTestCase.php',
-    'ArcanistVersionWorkflow' => 'workflow/ArcanistVersionWorkflow.php',
+    'ArcanistVersionWorkflow' => 'toolset/workflow/ArcanistVersionWorkflow.php',
     'ArcanistWeldWorkflow' => 'workflow/ArcanistWeldWorkflow.php',
     'ArcanistWhichWorkflow' => 'workflow/ArcanistWhichWorkflow.php',
     'ArcanistWildConfigOption' => 'config/option/ArcanistWildConfigOption.php',
diff --git a/src/runtime/ArcanistRuntime.php b/src/runtime/ArcanistRuntime.php
--- a/src/runtime/ArcanistRuntime.php
+++ b/src/runtime/ArcanistRuntime.php
@@ -168,32 +168,21 @@
     // NOTE: We don't have phutil_is_windows() yet here.
     $is_windows = (DIRECTORY_SEPARATOR != '/');
 
-    // We use stream_socket_pair() which is not available on Windows earlier.
-    $min_version = ($is_windows ? '5.3.0' : '5.2.3');
-    $cur_version = phpversion();
-    if (version_compare($cur_version, $min_version, '<')) {
-      $message = sprintf(
-        'You are running a version of PHP ("%s"), which is older than the '.
-        'minimum supported version ("%s"). Update PHP to continue.',
-        $cur_version,
-        $min_version);
-
-      throw new Exception($message);
-    }
+    // NOTE: There's a hard PHP version check earlier, in "init-script.php".
 
     if ($is_windows) {
       $need_functions = array(
-        'curl_init'     => array('builtin-dll', 'php_curl.dll'),
+        'curl_init' => array('builtin-dll', 'php_curl.dll'),
       );
     } else {
       $need_functions = array(
-        'curl_init'     => array(
+        'curl_init' => array(
           'text',
           "You need to install the cURL PHP extension, maybe with ".
           "'apt-get install php5-curl' or 'yum install php53-curl' or ".
           "something similar.",
         ),
-        'json_decode'   => array('flag', '--without-json'),
+        'json_decode' => array('flag', '--without-json'),
       );
     }
 
@@ -483,6 +472,7 @@
   private function newWorkflows(ArcanistToolset $toolset) {
     $workflows = id(new PhutilClassMapQuery())
       ->setAncestorClass('ArcanistWorkflow')
+      ->setContinueOnFailure(true)
       ->execute();
 
     foreach ($workflows as $key => $workflow) {
diff --git a/src/toolset/workflow/ArcanistVersionWorkflow.php b/src/toolset/workflow/ArcanistVersionWorkflow.php
new file mode 100644
--- /dev/null
+++ b/src/toolset/workflow/ArcanistVersionWorkflow.php
@@ -0,0 +1,78 @@
+<?php
+
+/**
+ * Display the current version of Arcanist.
+ */
+final class ArcanistVersionWorkflow extends ArcanistWorkflow {
+
+  public function supportsToolset(ArcanistToolset $toolset) {
+    return true;
+  }
+
+  public function getWorkflowName() {
+    return 'version';
+  }
+
+  public function getWorkflowInformation() {
+    // TOOLSETS: Expand this help.
+
+    $help = pht(<<<EOTEXT
+Shows the current version.
+EOTEXT
+);
+
+    return $this->newWorkflowInformation()
+      ->addExample(pht('**version**'))
+      ->setHelp($help);
+  }
+
+  public function getWorkflowArguments() {
+    return array();
+  }
+
+  public function runWorkflow() {
+    // TOOLSETS: Show the toolset version, not just the "arc" version.
+
+    $console = PhutilConsole::getConsole();
+
+    if (!Filesystem::binaryExists('git')) {
+      throw new ArcanistUsageException(
+        pht(
+          'Cannot display current version without "%s" installed.',
+          'git'));
+    }
+
+    $roots = array(
+      'arcanist' => dirname(phutil_get_library_root('arcanist')),
+    );
+
+    foreach ($roots as $lib => $root) {
+      $working_copy = ArcanistWorkingCopy::newFromWorkingDirectory($root);
+      $repository_api = $working_copy->newRepositoryAPI();
+
+      if (!$repository_api instanceof ArcanistGitAPI) {
+        throw new ArcanistUsageException(
+          pht(
+            'Library "%s" is not a Git working copy, so no version '.
+            'information can be provided.',
+            $lib));
+      }
+
+      // NOTE: Carefully execute these commands in a way that works on Windows
+      // until T8298 is properly fixed. See PHI52.
+
+      list($commit) = $repository_api->execxLocal('log -1 --format=%%H');
+      $commit = trim($commit);
+
+      list($timestamp) = $repository_api->execxLocal('log -1 --format=%%ct');
+      $timestamp = trim($timestamp);
+
+      $console->writeOut(
+        "%s %s (%s)\n",
+        $lib,
+        $commit,
+        date('j M Y', (int)$timestamp));
+    }
+  }
+
+}
diff --git a/src/workflow/ArcanistVersionWorkflow.php b/src/workflow/ArcanistVersionWorkflow.php
deleted file mode 100644
--- a/src/workflow/ArcanistVersionWorkflow.php
+++ /dev/null
@@ -1,70 +0,0 @@
-<?php
-
-/**
- * Display the current version of Arcanist.
- */
-final class ArcanistVersionWorkflow extends ArcanistWorkflow {
-
-  public function getWorkflowName() {
-    return 'version';
-  }
-
-  public function getCommandSynopses() {
-    return phutil_console_format(<<<EOTEXT
-      **version** [__options__]
-EOTEXT
-      );
-  }
-
-  public function getCommandHelp() {
-    return phutil_console_format(pht(<<<EOTEXT
-          Supports: cli
-          Shows the current version of arcanist.
-EOTEXT
-      ));
-  }
-
-  public function run() {
-    $console = PhutilConsole::getConsole();
-
-    if (!Filesystem::binaryExists('git')) {
-      throw new ArcanistUsageException(
-        pht(
-          'Cannot display current version without having `%s` installed.',
-          'git'));
-    }
-
-    $roots = array(
-      'arcanist' => dirname(phutil_get_library_root('arcanist')),
-    );
-
-    foreach ($roots as $lib => $root) {
-      $working_copy = ArcanistWorkingCopyIdentity::newFromPath($root);
-      $configuration_manager = clone $this->getConfigurationManager();
-      $configuration_manager->setWorkingCopyIdentity($working_copy);
-      $repository = ArcanistRepositoryAPI::newAPIFromConfigurationManager(
-        $configuration_manager);
-
-      if (!Filesystem::pathExists($repository->getMetadataPath())) {
-        throw new ArcanistUsageException(
-          pht('%s is not a git working copy.', $lib));
-      }
-
-      // NOTE: Carefully execute these commands in a way that works on Windows
-      // until T8298 is properly fixed. See PHI52.
-
-      list($commit) = $repository->execxLocal('log -1 --format=%%H');
-      $commit = trim($commit);
-
-      list($timestamp) = $repository->execxLocal('log -1 --format=%%ct');
-      $timestamp = trim($timestamp);
-
-      $console->writeOut(
-        "%s %s (%s)\n",
-        $lib,
-        $commit,
-        date('j M Y', (int)$timestamp));
-    }
-  }
-
-}