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
@@ -51,6 +51,7 @@
     'AphrontFormTextWithSubmitControl' => 'view/form/control/AphrontFormTextWithSubmitControl.php',
     'AphrontFormToggleButtonsControl' => 'view/form/control/AphrontFormToggleButtonsControl.php',
     'AphrontFormTokenizerControl' => 'view/form/control/AphrontFormTokenizerControl.php',
+    'AphrontFormTypeaheadControl' => 'view/form/control/AphrontFormTypeaheadControl.php',
     'AphrontFormView' => 'view/form/AphrontFormView.php',
     'AphrontGlyphBarView' => 'view/widget/bars/AphrontGlyphBarView.php',
     'AphrontHTMLResponse' => 'aphront/response/AphrontHTMLResponse.php',
@@ -524,6 +525,7 @@
     'DiffusionPathIDQuery' => 'applications/diffusion/query/pathid/DiffusionPathIDQuery.php',
     'DiffusionPathQuery' => 'applications/diffusion/query/DiffusionPathQuery.php',
     'DiffusionPathQueryTestCase' => 'applications/diffusion/query/pathid/__tests__/DiffusionPathQueryTestCase.php',
+    'DiffusionPathTreeController' => 'applications/diffusion/controller/DiffusionPathTreeController.php',
     'DiffusionPathValidateController' => 'applications/diffusion/controller/DiffusionPathValidateController.php',
     'DiffusionPushEventViewController' => 'applications/diffusion/controller/DiffusionPushEventViewController.php',
     'DiffusionPushLogController' => 'applications/diffusion/controller/DiffusionPushLogController.php',
@@ -2704,6 +2706,7 @@
     'AphrontFormTextWithSubmitControl' => 'AphrontFormControl',
     'AphrontFormToggleButtonsControl' => 'AphrontFormControl',
     'AphrontFormTokenizerControl' => 'AphrontFormControl',
+    'AphrontFormTypeaheadControl' => 'AphrontFormControl',
     'AphrontFormView' => 'AphrontView',
     'AphrontGlyphBarView' => 'AphrontBarView',
     'AphrontHTMLResponse' => 'AphrontResponse',
@@ -3164,6 +3167,7 @@
     'DiffusionMirrorEditController' => 'DiffusionController',
     'DiffusionPathCompleteController' => 'DiffusionController',
     'DiffusionPathQueryTestCase' => 'PhabricatorTestCase',
+    'DiffusionPathTreeController' => 'DiffusionController',
     'DiffusionPathValidateController' => 'DiffusionController',
     'DiffusionPushEventViewController' => 'DiffusionPushLogController',
     'DiffusionPushLogController' => 'DiffusionController',
diff --git a/src/applications/diffusion/application/PhabricatorApplicationDiffusion.php b/src/applications/diffusion/application/PhabricatorApplicationDiffusion.php
--- a/src/applications/diffusion/application/PhabricatorApplicationDiffusion.php
+++ b/src/applications/diffusion/application/PhabricatorApplicationDiffusion.php
@@ -85,6 +85,7 @@
             'hosting/' => 'DiffusionRepositoryEditHostingController',
             '(?P<serve>serve)/' => 'DiffusionRepositoryEditHostingController',
           ),
+          'pathtree/(?P<dblob>.*)' => 'DiffusionPathTreeController',
           'mirror/' => array(
             'edit/(?:(?P<id>\d+)/)?' => 'DiffusionMirrorEditController',
             'delete/(?P<id>\d+)/' => 'DiffusionMirrorDeleteController',
diff --git a/src/applications/diffusion/conduit/ConduitAPI_diffusion_querypaths_Method.php b/src/applications/diffusion/conduit/ConduitAPI_diffusion_querypaths_Method.php
--- a/src/applications/diffusion/conduit/ConduitAPI_diffusion_querypaths_Method.php
+++ b/src/applications/diffusion/conduit/ConduitAPI_diffusion_querypaths_Method.php
@@ -15,7 +15,7 @@
     return array(
       'path' => 'required string',
       'commit' => 'required string',
-      'pattern' => 'required string',
+      'pattern' => 'optional string',
       'limit' => 'optional int',
       'offset' => 'optional int',
     );
@@ -40,6 +40,7 @@
       $commit,
       $path);
 
+
     $lines = id(new LinesOfALargeExecFuture($future))->setDelimiter("\0");
     return $this->filterResults($lines, $request);
   }
@@ -65,23 +66,35 @@
         $lines[] = $path;
       }
     }
+
     return $this->filterResults($lines, $request);
   }
 
   protected function filterResults($lines, ConduitAPIRequest $request) {
     $pattern = $request->getValue('pattern');
-    $limit = $request->getValue('limit');
-    $offset = $request->getValue('offset');
+    $limit = (int)$request->getValue('limit');
+    $offset = (int)$request->getValue('offset');
+
+    if (strlen($pattern)) {
+      $pattern = '/'.preg_quote($pattern, '/').'/';
+    }
 
     $results = array();
+    $count = 0;
     foreach ($lines as $line) {
-      if (preg_match('#'.str_replace('#', '\#', $pattern).'#', $line)) {
-        $results[] = $line;
-        if (count($results) >= $offset + $limit) {
+      if (!$pattern || preg_match($pattern, $line)) {
+        if ($count >= $offset) {
+          $results[] = $line;
+        }
+
+        $count++;
+
+        if ($limit && ($count >= ($offset + $limit))) {
           break;
         }
       }
     }
+
     return $results;
   }
 }
diff --git a/src/applications/diffusion/controller/DiffusionPathTreeController.php b/src/applications/diffusion/controller/DiffusionPathTreeController.php
new file mode 100644
--- /dev/null
+++ b/src/applications/diffusion/controller/DiffusionPathTreeController.php
@@ -0,0 +1,36 @@
+<?php
+
+final class DiffusionPathTreeController extends DiffusionController {
+
+  public function processRequest() {
+    $drequest = $this->getDiffusionRequest();
+
+    if (!$drequest->getRepository()->canUsePathTree()) {
+      return new Aphront404Response();
+    }
+
+    $paths = $this->callConduitWithDiffusionRequest(
+      'diffusion.querypaths',
+      array(
+        'path' => $drequest->getPath(),
+        'commit' => $drequest->getCommit(),
+      ));
+
+    $tree = array();
+    foreach ($paths as $path) {
+      $parts = preg_split('((?<=/))', $path);
+      $cursor = &$tree;
+      foreach ($parts as $part) {
+        if (!is_array($cursor)) {
+          $cursor = array();
+        }
+        if (!isset($cursor[$part])) {
+          $cursor[$part] = 1;
+        }
+        $cursor = &$cursor[$part];
+      }
+    }
+
+    return id(new AphrontAjaxResponse())->setContent(array('tree' => $tree));
+  }
+}
diff --git a/src/applications/diffusion/controller/DiffusionRepositoryController.php b/src/applications/diffusion/controller/DiffusionRepositoryController.php
--- a/src/applications/diffusion/controller/DiffusionRepositoryController.php
+++ b/src/applications/diffusion/controller/DiffusionRepositoryController.php
@@ -366,9 +366,9 @@
     $button->setTag('a');
     $button->setIcon($icon);
     $button->setHref($drequest->generateURI(
-            array(
-              'action' => 'tags',
-            )));
+      array(
+        'action' => 'tags',
+      )));
 
     $header->addActionLink($button);
 
@@ -529,6 +529,33 @@
 
     $header->addActionLink($button);
     $browse_panel->setHeader($header);
+
+    if ($repository->canUsePathTree()) {
+      Javelin::initBehavior(
+        'diffusion-locate-file',
+        array(
+          'controlID' => 'locate-control',
+          'inputID' => 'locate-input',
+          'browseBaseURI' => (string)$drequest->generateURI(
+            array(
+              'action' => 'browse',
+            )),
+          'uri' => (string)$drequest->generateURI(
+            array(
+              'action' => 'pathtree',
+            )),
+        ));
+
+      $form = id(new AphrontFormView())
+        ->setUser($viewer)
+        ->appendChild(
+          id(new AphrontFormTypeaheadControl())
+            ->setHardpointID('locate-control')
+            ->setID('locate-input')
+            ->setLabel(pht('Locate File')));
+      $browse_panel->appendChild($form->buildLayoutView());
+    }
+
     $browse_panel->appendChild($browse_table);
 
     return $browse_panel;
diff --git a/src/applications/diffusion/request/DiffusionRequest.php b/src/applications/diffusion/request/DiffusionRequest.php
--- a/src/applications/diffusion/request/DiffusionRequest.php
+++ b/src/applications/diffusion/request/DiffusionRequest.php
@@ -520,6 +520,7 @@
       case 'tags':
       case 'branches':
       case 'lint':
+      case 'pathtree':
         $uri = "/diffusion/{$callsign}{$action}/{$path}{$commit}{$line}";
         break;
       case 'branch':
diff --git a/src/applications/repository/storage/PhabricatorRepository.php b/src/applications/repository/storage/PhabricatorRepository.php
--- a/src/applications/repository/storage/PhabricatorRepository.php
+++ b/src/applications/repository/storage/PhabricatorRepository.php
@@ -1191,6 +1191,10 @@
     return Filesystem::isDescendant($this->getLocalPath(), $default_path);
   }
 
+  public function canUsePathTree() {
+    return !$this->isSVN();
+  }
+
   public function canMirror() {
     if ($this->isGit() || $this->isHg()) {
       return true;
diff --git a/src/view/form/control/AphrontFormTypeaheadControl.php b/src/view/form/control/AphrontFormTypeaheadControl.php
new file mode 100644
--- /dev/null
+++ b/src/view/form/control/AphrontFormTypeaheadControl.php
@@ -0,0 +1,39 @@
+<?php
+
+final class AphrontFormTypeaheadControl extends AphrontFormControl {
+
+  private $hardpointID;
+
+  public function setHardpointID($hardpoint_id) {
+    $this->hardpointID = $hardpoint_id;
+    return $this;
+  }
+
+  public function getHardpointID() {
+    return $this->hardpointID;
+  }
+
+  protected function getCustomControlClass() {
+    return 'aphront-form-control-typeahead';
+  }
+
+  protected function renderInput() {
+    return javelin_tag(
+      'div',
+      array(
+        'style' => 'position: relative;',
+        'id' => $this->getHardpointID(),
+      ),
+      javelin_tag(
+        'input',
+        array(
+          'type'         => 'text',
+          'name'         => $this->getName(),
+          'value'        => $this->getValue(),
+          'disabled'     => $this->getDisabled() ? 'disabled' : null,
+          'autocomplete' => 'off',
+          'id'           => $this->getID(),
+        )));
+  }
+
+}
diff --git a/webroot/rsrc/css/aphront/table-view.css b/webroot/rsrc/css/aphront/table-view.css
--- a/webroot/rsrc/css/aphront/table-view.css
+++ b/webroot/rsrc/css/aphront/table-view.css
@@ -268,5 +268,13 @@
 }
 
 .phui-object-box .aphront-table-view {
+  border-style: solid;
+  border-width: 1px 0 0 0;
+  border-color: {$lightblueborder};
+}
+
+/* When a table immediately follows a header, remove the top border. */
+.phui-object-box .phui-header-shell +
+  .aphront-table-wrap .aphront-table-view {
   border: none;
 }
diff --git a/webroot/rsrc/css/aphront/typeahead.css b/webroot/rsrc/css/aphront/typeahead.css
--- a/webroot/rsrc/css/aphront/typeahead.css
+++ b/webroot/rsrc/css/aphront/typeahead.css
@@ -18,6 +18,12 @@
   margin: -1px 1% 0;
 }
 
+.aphront-form-control-typeahead div.jx-typeahead-results {
+  width: 100%;
+  margin: 0;
+  box-sizing: border-box;
+}
+
 div.jx-typeahead-results a.jx-result {
   color: #333;
   display: block;
@@ -51,3 +57,16 @@
 div.jx-tokenizer-container-focused.jx-typeahead-waiting {
   border-color: {$lightblueborder};
 }
+
+div.jx-typeahead-results a.diffusion-locate-file {
+ padding: 4px 8px;
+ color: {$darkgreytext}
+}
+
+.diffusion-locate-file strong {
+  color: {$blue};
+}
+
+.diffusion-locate-file .phui-icon-view {
+  padding-right: 8px;
+}
diff --git a/webroot/rsrc/externals/javelin/lib/control/typeahead/source/TypeaheadPreloadedSource.js b/webroot/rsrc/externals/javelin/lib/control/typeahead/source/TypeaheadPreloadedSource.js
--- a/webroot/rsrc/externals/javelin/lib/control/typeahead/source/TypeaheadPreloadedSource.js
+++ b/webroot/rsrc/externals/javelin/lib/control/typeahead/source/TypeaheadPreloadedSource.js
@@ -53,6 +53,10 @@
         this.matchResults(this.lastValue);
       }
       this.ready = true;
+    },
+
+    setReady: function(ready) {
+      this.ready = ready;
     }
   }
 });
diff --git a/webroot/rsrc/js/application/diffusion/DiffusionLocateFileSource.js b/webroot/rsrc/js/application/diffusion/DiffusionLocateFileSource.js
new file mode 100644
--- /dev/null
+++ b/webroot/rsrc/js/application/diffusion/DiffusionLocateFileSource.js
@@ -0,0 +1,289 @@
+/**
+ * @provides javelin-diffusion-locate-file-source
+ * @requires javelin-install
+ *           javelin-dom
+ *           javelin-typeahead-preloaded-source
+ *           javelin-util
+ * @javelin
+ */
+
+JX.install('DiffusionLocateFileSource', {
+
+  extend: 'TypeaheadPreloadedSource',
+
+  construct: function(uri) {
+    JX.TypeaheadPreloadedSource.call(this, uri);
+    this.cache = {};
+  },
+
+  members: {
+    tree: null,
+    limit: 20,
+    cache: null,
+
+    ondata: function(results) {
+      this.tree = results.tree;
+      this.setReady(true);
+    },
+
+
+    /**
+     * Match a query and show results in the typeahead.
+     */
+    matchResults: function(value, partial) {
+      // For now, just pretend spaces don't exist.
+      var search = value.toLowerCase();
+      search = search.replace(" ", "");
+
+      var paths = this.findResults(search);
+
+      var nodes = [];
+      for (var ii = 0; ii < paths.length; ii++) {
+        var path = paths[ii];
+        var name = [];
+        name.push(path.path.substr(0, path.pos));
+        name.push(
+          JX.$N('strong', {}, path.path.substr(path.pos, path.score)));
+
+        var pos = path.score;
+        var lower = path.path.toLowerCase();
+        for (var jj = path.pos + path.score; jj < path.path.length; jj++) {
+          if (lower.charAt(jj) == search.charAt(pos)) {
+            pos++;
+            name.push(JX.$N('strong', {}, path.path.charAt(jj)));
+            if (pos == search.length) {
+              break;
+            }
+          } else {
+            name.push(path.path.charAt(jj));
+          }
+        }
+
+        if (jj < path.path.length - 1 ) {
+          name.push(path.path.substr(jj + 1));
+        }
+
+        var attr = {
+          className: 'visual-only phui-icon-view phui-font-fa fa-file'
+        };
+        var icon = JX.$N('span', attr, '');
+
+        nodes.push(
+          JX.$N(
+            'a',
+            {
+              sigil: 'typeahead-result',
+              className: 'jx-result diffusion-locate-file',
+              ref: path.path
+            },
+            [icon, name]));
+      }
+
+      this.invoke('resultsready', nodes, value);
+      if (!partial) {
+        this.invoke('complete');
+      }
+    },
+
+
+    /**
+     * Find the results matching a query.
+     */
+    findResults: function(search) {
+      if (!search.length) {
+        return [];
+      }
+
+      // We know that the results for "abc" are always a subset of the results
+      // for "a" and "ab" -- and there's a good chance we already computed
+      // those result sets. Find the longest cached result which is a prefix
+      // of the search query.
+      var best = 0;
+      var start = this.tree;
+      for (var k in this.cache) {
+        if ((k.length <= search.length) &&
+            (k.length > best) &&
+            (search.substr(0, k.length) == k)) {
+          best = k.length;
+          start = this.cache[k];
+        }
+      }
+
+      var matches;
+      if (start === null) {
+        matches = null;
+      } else {
+        matches = this.matchTree(start, search, 0);
+      }
+
+      // Save this tree in cache; throw the cache away after a few minutes.
+      if (!(search in this.cache)) {
+        this.cache[search] = matches;
+        setTimeout(
+          JX.bind(this, function() { delete this.cache[search]; }),
+          1000 * 60 * 5);
+      }
+
+      if (!matches) {
+        return [];
+      }
+
+      var paths = [];
+      this.buildPaths(matches, paths, '', search, []);
+
+      paths.sort(
+        function(u, v) {
+          if (u.score != v.score) {
+            return (v.score - u.score);
+          }
+
+          if (u.pos != v.pos) {
+            return (u.pos - v.pos);
+          }
+
+          return ((u.path > v.path) ? 1 : -1);
+        });
+
+      var num =  Math.min(paths.length, this.limit);
+      var results = [];
+      for (var ii = 0; ii < num; ii++) {
+        results.push(paths[ii]);
+      }
+
+      return results;
+    },
+
+
+    /**
+     * Select the subtree that matches a query.
+     */
+    matchTree: function(tree, value, pos) {
+      var matches = null;
+      var count = 0;
+      for (var k in tree) {
+        var p = pos;
+
+        if (p != value.length) {
+          p = this.matchString(k, value, pos);
+        }
+
+        var result;
+        if (p == value.length) {
+          result = tree[k];
+        } else {
+          if (tree == 1) {
+            continue;
+          } else {
+            result = this.matchTree(tree[k], value, p);
+            if (!result) {
+              continue;
+            }
+          }
+        }
+
+        if (!matches) {
+          matches = {};
+        }
+        matches[k] = result;
+      }
+
+      return matches;
+    },
+
+
+    /**
+     * Look for the needle in a string, returning how much of it was found.
+     */
+    matchString: function(haystack, needle, pos) {
+      var str = haystack.toLowerCase();
+      var len = str.length;
+      for (var ii = 0; ii < len; ii++) {
+        if (str.charAt(ii) == needle.charAt(pos)) {
+          pos++;
+          if (pos == needle.length) {
+            break;
+          }
+        }
+      }
+      return pos;
+    },
+
+
+    /**
+     * Flatten a tree into paths.
+     */
+    buildPaths: function(matches, paths, prefix, search) {
+      var first = search.charAt(0);
+
+      for (var k in matches) {
+        if (matches[k] == 1) {
+          var path = prefix + k;
+          var lower = path.toLowerCase();
+
+          var best = 0;
+          var pos = 0;
+          for (var jj = 0; jj < lower.length; jj++) {
+            if (lower.charAt(jj) != first) {
+              continue;
+            }
+
+            var score = this.scoreMatch(lower, jj, search);
+            if (score == -1) {
+              break;
+            }
+
+            if (score > best) {
+              best = score;
+              pos = jj;
+              if (best == search.length) {
+                break;
+              }
+            }
+          }
+
+          paths.push({
+            path: path,
+            score: best,
+            pos: pos
+          });
+
+        } else {
+          this.buildPaths(matches[k], paths, prefix + k, search);
+        }
+      }
+    },
+
+
+    /**
+     * Score a matching string by finding the longest prefix of the search
+     * query it contains continguously.
+     */
+    scoreMatch: function(haystack, haypos, search) {
+      var pos = 0;
+      for (var ii = haypos; ii < haystack.length; ii++) {
+        if (haystack.charAt(ii) == search.charAt(pos)) {
+          pos++;
+          if (pos == search.length) {
+            return pos;
+          }
+        } else {
+          ii++;
+          break;
+        }
+      }
+
+      var rem = pos;
+      for (/* keep going */; ii < haystack.length; ii++) {
+        if (haystack.charAt(ii) == search.charAt(rem)) {
+          rem++;
+          if (rem == search.length) {
+            return pos;
+          }
+        }
+      }
+
+      return -1;
+    }
+
+  }
+});
diff --git a/webroot/rsrc/js/application/diffusion/behavior-locate-file.js b/webroot/rsrc/js/application/diffusion/behavior-locate-file.js
new file mode 100644
--- /dev/null
+++ b/webroot/rsrc/js/application/diffusion/behavior-locate-file.js
@@ -0,0 +1,31 @@
+/**
+ * @provides javelin-behavior-diffusion-locate-file
+ * @requires javelin-behavior
+ *           javelin-diffusion-locate-file-source
+ *           javelin-dom
+ *           javelin-typeahead
+ *           javelin-uri
+ */
+
+JX.behavior('diffusion-locate-file', function(config) {
+  var control = JX.$(config.controlID);
+  var input = JX.$(config.inputID);
+
+  var datasource = new JX.DiffusionLocateFileSource(config.uri);
+
+  var typeahead = new JX.Typeahead(control, input);
+  typeahead.setDatasource(datasource);
+
+  typeahead.listen('choose', function(r) {
+    JX.$U(config.browseBaseURI + r.ref).go();
+  });
+
+  var started = false;
+  JX.DOM.listen(input, 'click', null, function() {
+    if (!started) {
+      started = true;
+      typeahead.start();
+    }
+  });
+
+});