diff --git a/resources/sql/autopatches/20140210.projcfield.4.memmig.sql b/resources/sql/autopatches/20140210.projcfield.4.memmig.sql
new file mode 100644
index 0000000000..dde525bd29
--- /dev/null
+++ b/resources/sql/autopatches/20140210.projcfield.4.memmig.sql
@@ -0,0 +1,8 @@
+/* These are here so `grep` will find them if we ever change things: */
+
+/* PhabricatorEdgeConfig::TYPE_PROJ_MEMBER = 13 */
+/* PhabricatorEdgeConfig::TYPE_OBJECT_HAS_SUBSCRIBER = 21 */
+
+INSERT IGNORE INTO {$NAMESPACE}_project.edge (src, type, dst, dateCreated)
+  SELECT src, 21, dst, dateCreated FROM {$NAMESPACE}_project.edge
+    WHERE type = 13;
diff --git a/src/applications/metamta/query/PhabricatorMetaMTAMemberQuery.php b/src/applications/metamta/query/PhabricatorMetaMTAMemberQuery.php
index b0be1ab34e..f270f0089d 100644
--- a/src/applications/metamta/query/PhabricatorMetaMTAMemberQuery.php
+++ b/src/applications/metamta/query/PhabricatorMetaMTAMemberQuery.php
@@ -1,69 +1,69 @@
 <?php
 
 /**
  * Expands aggregate mail recipients into their component mailables. For
  * example, a project currently expands into all of its members.
  */
 final class PhabricatorMetaMTAMemberQuery extends PhabricatorQuery {
 
   private $phids = array();
   private $viewer;
 
   public function setViewer(PhabricatorUser $viewer) {
     $this->viewer = $viewer;
     return $this;
   }
 
   public function getViewer() {
     return $this->viewer;
   }
 
   public function withPHIDs(array $phids) {
     $this->phids = $phids;
     return $this;
   }
 
   public function execute() {
     $phids = array_fuse($this->phids);
     $actors = array();
     $type_map = array();
     foreach ($phids as $phid) {
       $type_map[phid_get_type($phid)][] = $phid;
     }
 
     // TODO: Generalize this somewhere else.
 
     $results = array();
     foreach ($type_map as $type => $phids) {
       switch ($type) {
         case PhabricatorProjectPHIDTypeProject::TYPECONST:
-          // TODO: For now, project members are always on the "mailing list"
-          // implied by the project, but we should differentiate members and
-          // subscribers (i.e., allow you to unsubscribe from mail about
-          // a project).
+          // NOTE: We're loading the projects here in order to respect policies.
 
           $projects = id(new PhabricatorProjectQuery())
             ->setViewer($this->getViewer())
-            ->needMembers(true)
             ->withPHIDs($phids)
             ->execute();
 
+          $subscribers = id(new PhabricatorSubscribersQuery())
+            ->withObjectPHIDs($phids)
+            ->execute();
+
           $projects = mpull($projects, null, 'getPHID');
           foreach ($phids as $phid) {
             $project = idx($projects, $phid);
             if (!$project) {
               $results[$phid] = array();
             } else {
-              $results[$phid] = $project->getMemberPHIDs();
+              $results[$phid] = idx($subscribers, $phid, array());
             }
           }
           break;
         default:
           break;
       }
     }
 
     return $results;
   }
 
 }
diff --git a/src/applications/project/editor/PhabricatorProjectTransactionEditor.php b/src/applications/project/editor/PhabricatorProjectTransactionEditor.php
index 43cc9924a8..4af23f781e 100644
--- a/src/applications/project/editor/PhabricatorProjectTransactionEditor.php
+++ b/src/applications/project/editor/PhabricatorProjectTransactionEditor.php
@@ -1,230 +1,256 @@
 <?php
 
 final class PhabricatorProjectTransactionEditor
   extends PhabricatorApplicationTransactionEditor {
 
   public function getTransactionTypes() {
     $types = parent::getTransactionTypes();
 
     $types[] = PhabricatorTransactions::TYPE_EDGE;
     $types[] = PhabricatorTransactions::TYPE_VIEW_POLICY;
     $types[] = PhabricatorTransactions::TYPE_EDIT_POLICY;
     $types[] = PhabricatorTransactions::TYPE_JOIN_POLICY;
 
     $types[] = PhabricatorProjectTransaction::TYPE_NAME;
     $types[] = PhabricatorProjectTransaction::TYPE_STATUS;
     $types[] = PhabricatorProjectTransaction::TYPE_IMAGE;
 
     return $types;
   }
 
   protected function getCustomTransactionOldValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhabricatorProjectTransaction::TYPE_NAME:
         return $object->getName();
       case PhabricatorProjectTransaction::TYPE_STATUS:
         return $object->getStatus();
       case PhabricatorProjectTransaction::TYPE_IMAGE:
         return $object->getProfileImagePHID();
     }
 
     return parent::getCustomTransactionOldValue($object, $xaction);
   }
 
   protected function getCustomTransactionNewValue(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhabricatorProjectTransaction::TYPE_NAME:
       case PhabricatorProjectTransaction::TYPE_STATUS:
       case PhabricatorProjectTransaction::TYPE_IMAGE:
         return $xaction->getNewValue();
     }
 
     return parent::getCustomTransactionNewValue($object, $xaction);
   }
 
   protected function applyCustomInternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhabricatorProjectTransaction::TYPE_NAME:
         $object->setName($xaction->getNewValue());
         return;
       case PhabricatorProjectTransaction::TYPE_STATUS:
         $object->setStatus($xaction->getNewValue());
         return;
       case PhabricatorProjectTransaction::TYPE_IMAGE:
         $object->setProfileImagePHID($xaction->getNewValue());
         return;
       case PhabricatorTransactions::TYPE_EDGE:
         return;
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
         $object->setViewPolicy($xaction->getNewValue());
         return;
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
         $object->setEditPolicy($xaction->getNewValue());
         return;
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
         $object->setJoinPolicy($xaction->getNewValue());
         return;
     }
 
     return parent::applyCustomInternalTransaction($object, $xaction);
   }
 
   protected function applyCustomExternalTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhabricatorProjectTransaction::TYPE_NAME:
         $old_slug = $object->getFullPhrictionSlug();
         $object->setPhrictionSlug($xaction->getNewValue());
         $changed_slug = $old_slug != $object->getFullPhrictionSlug();
         if ($xaction->getOldValue() && $changed_slug) {
           $old_document = id(new PhrictionDocument())
             ->loadOneWhere(
               'slug = %s',
               $old_slug);
           if ($old_document && $old_document->getStatus() ==
               PhrictionDocumentStatus::STATUS_EXISTS) {
             $content = id(new PhrictionContent())
               ->load($old_document->getContentID());
             $from_editor = id(PhrictionDocumentEditor::newForSlug($old_slug))
               ->setActor($this->getActor())
               ->setTitle($content->getTitle())
               ->setContent($content->getContent())
               ->setDescription($content->getDescription());
 
             $target_editor = id(PhrictionDocumentEditor::newForSlug(
               $object->getFullPhrictionSlug()))
               ->setActor($this->getActor())
               ->setTitle($content->getTitle())
               ->setContent($content->getContent())
               ->setDescription($content->getDescription())
               ->moveHere($old_document->getID(), $old_document->getPHID());
 
             $target_document = $target_editor->getDocument();
             $from_editor->moveAway($target_document->getID());
           }
         }
         return;
       case PhabricatorTransactions::TYPE_VIEW_POLICY:
       case PhabricatorTransactions::TYPE_EDIT_POLICY:
       case PhabricatorTransactions::TYPE_JOIN_POLICY:
-      case PhabricatorTransactions::TYPE_EDGE:
       case PhabricatorProjectTransaction::TYPE_STATUS:
       case PhabricatorProjectTransaction::TYPE_IMAGE:
         return;
+      case PhabricatorTransactions::TYPE_EDGE:
+        switch ($xaction->getMetadataValue('edge:type')) {
+          case PhabricatorEdgeConfig::TYPE_PROJ_MEMBER:
+            // When project members are added or removed, add or remove their
+            // subscriptions.
+            $old = $xaction->getOldValue();
+            $new = $xaction->getNewValue();
+            $add = array_keys(array_diff_key($new, $old));
+            $rem = array_keys(array_diff_key($old, $new));
+
+            // NOTE: The subscribe is "explicit" because there's no implicit
+            // unsubscribe, so Join -> Leave -> Join doesn't resubscribe you
+            // if we use an implicit subscribe, even though you never willfully
+            // unsubscribed. Not sure if adding implicit unsubscribe (which
+            // would not write the unsubscribe row) is justified to deal with
+            // this, which is a fairly weird edge case and pretty arguable both
+            // ways.
+
+            id(new PhabricatorSubscriptionsEditor())
+              ->setActor($this->requireActor())
+              ->setObject($object)
+              ->subscribeExplicit($add)
+              ->unsubscribe($rem)
+              ->save();
+            break;
+        }
+        return;
     }
 
     return parent::applyCustomExternalTransaction($object, $xaction);
   }
 
   protected function validateTransaction(
     PhabricatorLiskDAO $object,
     $type,
     array $xactions) {
 
     $errors = parent::validateTransaction($object, $type, $xactions);
 
     switch ($type) {
       case PhabricatorProjectTransaction::TYPE_NAME:
         $missing = $this->validateIsEmptyTextField(
           $object->getName(),
           $xactions);
 
         if ($missing) {
           $error = new PhabricatorApplicationTransactionValidationError(
             $type,
             pht('Required'),
             pht('Project name is required.'),
             nonempty(last($xactions), null));
 
           $error->setIsMissingFieldError(true);
           $errors[] = $error;
         }
         break;
     }
 
     return $errors;
   }
 
 
   protected function requireCapabilities(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhabricatorProjectTransaction::TYPE_NAME:
       case PhabricatorProjectTransaction::TYPE_STATUS:
       case PhabricatorProjectTransaction::TYPE_IMAGE:
         PhabricatorPolicyFilter::requireCapability(
           $this->requireActor(),
           $object,
           PhabricatorPolicyCapability::CAN_EDIT);
         return;
       case PhabricatorTransactions::TYPE_EDGE:
         switch ($xaction->getMetadataValue('edge:type')) {
           case PhabricatorEdgeConfig::TYPE_PROJ_MEMBER:
             $old = $xaction->getOldValue();
             $new = $xaction->getNewValue();
 
             $add = array_keys(array_diff_key($new, $old));
             $rem = array_keys(array_diff_key($old, $new));
 
             $actor_phid = $this->requireActor()->getPHID();
 
             $is_join = (($add === array($actor_phid)) && !$rem);
             $is_leave = (($rem === array($actor_phid)) && !$add);
 
             if ($is_join) {
               // You need CAN_JOIN to join a project.
               PhabricatorPolicyFilter::requireCapability(
                 $this->requireActor(),
                 $object,
                 PhabricatorPolicyCapability::CAN_JOIN);
             } else if ($is_leave) {
               // You don't need any capabilities to leave a project.
             } else {
               // You need CAN_EDIT to change members other than yourself.
               PhabricatorPolicyFilter::requireCapability(
                 $this->requireActor(),
                 $object,
                 PhabricatorPolicyCapability::CAN_EDIT);
             }
             return;
         }
         break;
     }
 
     return parent::requireCapabilities($object, $xaction);
   }
 
   protected function supportsSearch() {
     return true;
   }
 
   protected function extractFilePHIDsFromCustomTransaction(
     PhabricatorLiskDAO $object,
     PhabricatorApplicationTransaction $xaction) {
 
     switch ($xaction->getTransactionType()) {
       case PhabricatorProjectTransaction::TYPE_IMAGE:
         $new = $xaction->getNewValue();
         if ($new) {
           return array($new);
         }
         break;
     }
 
     return parent::extractFilePHIDsFromCustomTransaction($object, $xaction);
   }
 
 }
diff --git a/src/applications/project/storage/PhabricatorProject.php b/src/applications/project/storage/PhabricatorProject.php
index 560f2e0797..c0979186cb 100644
--- a/src/applications/project/storage/PhabricatorProject.php
+++ b/src/applications/project/storage/PhabricatorProject.php
@@ -1,199 +1,199 @@
 <?php
 
 final class PhabricatorProject extends PhabricatorProjectDAO
   implements
     PhabricatorFlaggableInterface,
     PhabricatorPolicyInterface,
     PhabricatorSubscribableInterface,
     PhabricatorCustomFieldInterface {
 
   protected $name;
   protected $status = PhabricatorProjectStatus::STATUS_ACTIVE;
   protected $authorPHID;
   protected $subprojectPHIDs = array();
   protected $phrictionSlug;
   protected $profileImagePHID;
 
   protected $viewPolicy;
   protected $editPolicy;
   protected $joinPolicy;
 
   private $memberPHIDs = self::ATTACHABLE;
   private $sparseMembers = self::ATTACHABLE;
   private $customFields = self::ATTACHABLE;
   private $profileImageFile = self::ATTACHABLE;
 
   public static function initializeNewProject(PhabricatorUser $actor) {
     return id(new PhabricatorProject())
       ->setName('')
       ->setAuthorPHID($actor->getPHID())
       ->setViewPolicy(PhabricatorPolicies::POLICY_USER)
       ->setEditPolicy(PhabricatorPolicies::POLICY_USER)
       ->setJoinPolicy(PhabricatorPolicies::POLICY_USER)
       ->attachMemberPHIDs(array());
   }
 
   public function getCapabilities() {
     return array(
       PhabricatorPolicyCapability::CAN_VIEW,
       PhabricatorPolicyCapability::CAN_EDIT,
       PhabricatorPolicyCapability::CAN_JOIN,
     );
   }
 
   public function getPolicy($capability) {
     switch ($capability) {
       case PhabricatorPolicyCapability::CAN_VIEW:
         return $this->getViewPolicy();
       case PhabricatorPolicyCapability::CAN_EDIT:
         return $this->getEditPolicy();
       case PhabricatorPolicyCapability::CAN_JOIN:
         return $this->getJoinPolicy();
     }
   }
 
   public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
 
     switch ($capability) {
       case PhabricatorPolicyCapability::CAN_VIEW:
         if ($this->isUserMember($viewer->getPHID())) {
           // Project members can always view a project.
           return true;
         }
         break;
       case PhabricatorPolicyCapability::CAN_EDIT:
         break;
       case PhabricatorPolicyCapability::CAN_JOIN:
         $can_edit = PhabricatorPolicyCapability::CAN_EDIT;
         if (PhabricatorPolicyFilter::hasCapability($viewer, $this, $can_edit)) {
           // Project editors can always join a project.
           return true;
         }
         break;
     }
 
     return false;
   }
 
   public function describeAutomaticCapability($capability) {
     switch ($capability) {
       case PhabricatorPolicyCapability::CAN_VIEW:
         return pht("Members of a project can always view it.");
       case PhabricatorPolicyCapability::CAN_JOIN:
         return pht("Users who can edit a project can always join it.");
     }
     return null;
   }
 
   public function isUserMember($user_phid) {
     if ($this->memberPHIDs !== self::ATTACHABLE) {
       return in_array($user_phid, $this->memberPHIDs);
     }
     return $this->assertAttachedKey($this->sparseMembers, $user_phid);
   }
 
   public function setIsUserMember($user_phid, $is_member) {
     if ($this->sparseMembers === self::ATTACHABLE) {
       $this->sparseMembers = array();
     }
     $this->sparseMembers[$user_phid] = $is_member;
     return $this;
   }
 
   public function getConfiguration() {
     return array(
       self::CONFIG_AUX_PHID => true,
       self::CONFIG_SERIALIZATION => array(
         'subprojectPHIDs' => self::SERIALIZATION_JSON,
       ),
     ) + parent::getConfiguration();
   }
 
   public function generatePHID() {
     return PhabricatorPHID::generateNewPHID(
       PhabricatorProjectPHIDTypeProject::TYPECONST);
   }
 
   public function attachMemberPHIDs(array $phids) {
     $this->memberPHIDs = $phids;
     return $this;
   }
 
   public function getMemberPHIDs() {
     return $this->assertAttached($this->memberPHIDs);
   }
 
   public function setPhrictionSlug($slug) {
 
     // NOTE: We're doing a little magic here and stripping out '/' so that
     // project pages always appear at top level under projects/ even if the
     // display name is "Hack / Slash" or similar (it will become
     // 'hack_slash' instead of 'hack/slash').
 
     $slug = str_replace('/', ' ', $slug);
     $slug = PhabricatorSlug::normalize($slug);
     $this->phrictionSlug = $slug;
     return $this;
   }
 
   public function getFullPhrictionSlug() {
     $slug = $this->getPhrictionSlug();
     return 'projects/'.$slug;
   }
 
   public function isArchived() {
     return ($this->getStatus() == PhabricatorProjectStatus::STATUS_ARCHIVED);
   }
 
   public function getProfileImageURI() {
     return $this->getProfileImageFile()->getBestURI();
   }
 
   public function attachProfileImageFile(PhabricatorFile $file) {
     $this->profileImageFile = $file;
     return $this;
   }
 
   public function getProfileImageFile() {
     return $this->assertAttached($this->profileImageFile);
   }
 
 
 /* -(  PhabricatorSubscribableInterface  )----------------------------------- */
 
 
   public function isAutomaticallySubscribed($phid) {
     return false;
   }
 
   public function shouldShowSubscribersProperty() {
     return false;
   }
 
   public function shouldAllowSubscription($phid) {
-    return false;
+    return $this->isUserMember($phid);
   }
 
 
 /* -(  PhabricatorCustomFieldInterface  )------------------------------------ */
 
 
   public function getCustomFieldSpecificationForRole($role) {
     return PhabricatorEnv::getEnvConfig('projects.fields');
   }
 
   public function getCustomFieldBaseClass() {
     return 'PhabricatorProjectCustomField';
   }
 
   public function getCustomFields() {
     return $this->assertAttached($this->customFields);
   }
 
   public function attachCustomFields(PhabricatorCustomFieldAttachment $fields) {
     $this->customFields = $fields;
     return $this;
   }
 
 
 }