diff --git a/.babelrc b/.babelrc
index 92a64c2a4..ed21974ac 100644
--- a/.babelrc
+++ b/.babelrc
@@ -1,6 +1,6 @@
 {
   "presets": [
-    ["es2015", {modules: false}]
+    ["es2015", {"modules": false}]
   ],
   "plugins": [
     "transform-class-properties",
diff --git a/.gitignore b/.gitignore
index 6f3ac70b8..6f3104629 100644
--- a/.gitignore
+++ b/.gitignore
@@ -30,6 +30,7 @@ plugins/*
 !plugins/talk-plugin-author-menu
 !plugins/talk-plugin-comment-content
 !plugins/talk-plugin-deep-reply-count
+!plugins/talk-plugin-downvote
 !plugins/talk-plugin-facebook-auth
 !plugins/talk-plugin-featured-comments
 !plugins/talk-plugin-flag-details
@@ -52,14 +53,17 @@ plugins/*
 !plugins/talk-plugin-remember-sort
 !plugins/talk-plugin-respect
 !plugins/talk-plugin-slack-notifications
+!plugins/talk-plugin-sort-most-downvoted
 !plugins/talk-plugin-sort-most-liked
 !plugins/talk-plugin-sort-most-loved
 !plugins/talk-plugin-sort-most-replied
 !plugins/talk-plugin-sort-most-respected
+!plugins/talk-plugin-sort-most-upvoted
 !plugins/talk-plugin-sort-newest
 !plugins/talk-plugin-sort-oldest
 !plugins/talk-plugin-subscriber
 !plugins/talk-plugin-toxic-comments
+!plugins/talk-plugin-upvote
 !plugins/talk-plugin-viewing-options
 !plugins/talk-plugin-rich-text
 
diff --git a/package.json b/package.json
index c2cd648e1..a807d3321 100644
--- a/package.json
+++ b/package.json
@@ -126,6 +126,7 @@
     "inquirer": "^3.2.2",
     "inquirer-autocomplete-prompt": "^0.12.1",
     "ioredis": "3.1.4",
+    "ip": "^1.1.5",
     "joi": "^13.0.0",
     "jsonwebtoken": "^8.0.0",
     "jwt-decode": "^2.2.0",
@@ -143,6 +144,7 @@
     "morgan": "^1.9.0",
     "ms": "^2.0.0",
     "murmurhash-js": "^1.0.0",
+    "name-all-modules-plugin": "^1.0.1",
     "node-emoji": "^1.8.1",
     "node-fetch": "^1.7.2",
     "nodemailer": "^2.6.4",
@@ -195,6 +197,7 @@
     "url-search-params": "^0.9.0",
     "uuid": "^3.1.0",
     "webpack": "^3.10.0",
+    "webpack-manifest-plugin": "^2.0.0-rc.2",
     "webpack-sources": "^1.0.1",
     "yaml-loader": "^0.4.0",
     "yamljs": "^0.2.10"
@@ -216,19 +219,16 @@
     "eslint-plugin-mocha": "^4.11.0",
     "husky": "^0.14.3",
     "identity-obj-proxy": "^3.0.0",
-    "ip": "^1.1.5",
     "jest": "^21.2.1",
     "jest-junit": "^3.6.0",
     "lint-staged": "^7.0.0",
     "mocha": "^3.1.2",
     "mocha-junit-reporter": "^1.12.1",
-    "name-all-modules-plugin": "^1.0.1",
     "nightwatch": "^0.9.16",
     "nodemon": "^1.11.0",
     "selenium-standalone": "^6.11.0",
     "sinon": "^3.2.1",
     "sinon-chai": "^2.13.0",
-    "webpack-manifest-plugin": "^2.0.0-rc.2",
     "yaml-lint": "^1.0.0"
   },
   "engines": {
diff --git a/plugins/talk-plugin-downvote/client/.eslintrc.json b/plugins/talk-plugin-downvote/client/.eslintrc.json
new file mode 100644
index 000000000..9fe56bd14
--- /dev/null
+++ b/plugins/talk-plugin-downvote/client/.eslintrc.json
@@ -0,0 +1,23 @@
+{
+  "env": {
+    "browser": true,
+    "es6": true,
+    "mocha": true
+  },
+  "parserOptions": {
+    "sourceType": "module",
+    "ecmaFeatures": {
+      "experimentalObjectRestSpread": true,
+      "jsx": true
+    }
+  },
+  "parser": "babel-eslint",
+  "plugins": [
+    "react"
+  ],
+  "rules": {
+    "react/jsx-uses-react": "error",
+    "react/jsx-uses-vars": "error",
+    "no-console": ["warn", { "allow": ["warn", "error"] }]
+  }
+}
diff --git a/plugins/talk-plugin-downvote/client/components/DownvoteButton.css b/plugins/talk-plugin-downvote/client/components/DownvoteButton.css
new file mode 100644
index 000000000..71090306b
--- /dev/null
+++ b/plugins/talk-plugin-downvote/client/components/DownvoteButton.css
@@ -0,0 +1,39 @@
+.container {
+  display: inline-block;
+}
+
+.button {
+  color: #2a2a2a;
+  margin: 5px 10px 5px 0px;
+  background: none;
+  padding: 0px;
+  border: none;
+  font-size: inherit;
+  vertical-align: middle;
+
+  &:hover {
+    color: #767676;
+    cursor: pointer;
+  }
+
+  &.downvoted {
+    color: #cc0000;
+
+    &:hover {
+      color: #ff3232;
+      cursor: pointer;
+    }
+  }
+}
+
+.icon {
+  font-size: 12px;
+  padding: 0 3px;
+}
+
+@media (max-width: 425px) {
+  .label {
+    display: none;
+  }
+}
+
diff --git a/plugins/talk-plugin-downvote/client/components/DownvoteButton.js b/plugins/talk-plugin-downvote/client/components/DownvoteButton.js
new file mode 100644
index 000000000..2bf34260b
--- /dev/null
+++ b/plugins/talk-plugin-downvote/client/components/DownvoteButton.js
@@ -0,0 +1,56 @@
+import React from 'react';
+import Icon from './Icon';
+import styles from './DownvoteButton.css';
+import { withReaction } from 'plugin-api/beta/client/hocs';
+import cn from 'classnames';
+
+const plugin = 'talk-plugin-downvote';
+
+class DownvoteButton extends React.Component {
+  handleClick = () => {
+    const {
+      postReaction,
+      deleteReaction,
+      showSignInDialog,
+      alreadyReacted,
+      user,
+    } = this.props;
+
+    // If the current user does not exist, trigger sign in dialog.
+    if (!user) {
+      showSignInDialog();
+      return;
+    }
+
+    if (alreadyReacted) {
+      deleteReaction();
+    } else {
+      postReaction();
+    }
+  };
+
+  render() {
+    const { count, alreadyReacted } = this.props;
+    return (
+      <div className={cn(styles.container, `${plugin}-container`)}>
+        <button
+          className={cn(
+            styles.button,
+            {
+              [`${
+                styles.downvoted
+              } talk-plugin-downvote-downvoted`]: alreadyReacted,
+            },
+            `${plugin}-button`
+          )}
+          onClick={this.handleClick}
+        >
+          <Icon className={cn(styles.icon, `${plugin}-icon`)} />
+          <span className={cn(`${plugin}-count`)}>{count > 0 && count}</span>
+        </button>
+      </div>
+    );
+  }
+}
+
+export default withReaction('downvote')(DownvoteButton);
diff --git a/plugins/talk-plugin-downvote/client/components/Icon.js b/plugins/talk-plugin-downvote/client/components/Icon.js
new file mode 100644
index 000000000..56f43029d
--- /dev/null
+++ b/plugins/talk-plugin-downvote/client/components/Icon.js
@@ -0,0 +1,10 @@
+import React from 'react';
+import cn from 'classnames';
+
+// @TODO change icon when we deprecate FA
+export default ({ className }) => (
+  <i
+    className={cn('fa', 'fa-arrow-circle-down', className)}
+    aria-hidden="true"
+  />
+);
diff --git a/plugins/talk-plugin-downvote/client/index.js b/plugins/talk-plugin-downvote/client/index.js
new file mode 100644
index 000000000..dc60178db
--- /dev/null
+++ b/plugins/talk-plugin-downvote/client/index.js
@@ -0,0 +1,7 @@
+import DownvoteButton from './components/DownvoteButton';
+
+export default {
+  slots: {
+    commentReactions: [DownvoteButton],
+  },
+};
diff --git a/plugins/talk-plugin-downvote/index.js b/plugins/talk-plugin-downvote/index.js
new file mode 100644
index 000000000..c0e29c5ef
--- /dev/null
+++ b/plugins/talk-plugin-downvote/index.js
@@ -0,0 +1,2 @@
+const { getReactionConfig } = require('../../plugin-api/beta/server');
+module.exports = getReactionConfig('downvote');
diff --git a/plugins/talk-plugin-downvote/package.json b/plugins/talk-plugin-downvote/package.json
new file mode 100644
index 000000000..440d18b6a
--- /dev/null
+++ b/plugins/talk-plugin-downvote/package.json
@@ -0,0 +1,9 @@
+{
+  "name": "@coralproject/talk-plugin-downvote",
+  "pluginName": "talk-plugin-downvote",
+  "version": "0.0.1",
+  "description": "Downvote comments",
+  "main": "index.js",
+  "author": "The Coral Project Team <coral@mozillafoundation.org>",
+  "license": "Apache-2.0"
+}
diff --git a/plugins/talk-plugin-respect/client/Icon.js b/plugins/talk-plugin-respect/client/Icon.js
index 8b45615aa..9af30b86a 100644
--- a/plugins/talk-plugin-respect/client/Icon.js
+++ b/plugins/talk-plugin-respect/client/Icon.js
@@ -1,6 +1,7 @@
 import React from 'react';
 import cn from 'classnames';
 
+// @TODO change icon when we deprecate FA
 export default ({ className }) => (
   <i className={cn('fa', 'fa-handshake-o', className)} aria-hidden="true" />
 );
diff --git a/plugins/talk-plugin-sort-most-downvoted/client/.eslintrc.json b/plugins/talk-plugin-sort-most-downvoted/client/.eslintrc.json
new file mode 100644
index 000000000..c8a6db18a
--- /dev/null
+++ b/plugins/talk-plugin-sort-most-downvoted/client/.eslintrc.json
@@ -0,0 +1,3 @@
+{
+  "extends": "@coralproject/eslint-config-talk/client"
+}
diff --git a/plugins/talk-plugin-sort-most-downvoted/client/index.js b/plugins/talk-plugin-sort-most-downvoted/client/index.js
new file mode 100644
index 000000000..fb6ad544c
--- /dev/null
+++ b/plugins/talk-plugin-sort-most-downvoted/client/index.js
@@ -0,0 +1,19 @@
+import translations from './translations.yml';
+import { createSortOption } from 'talk-plugin-viewing-options/client/api/factories';
+import { t } from 'plugin-api/beta/client/services';
+
+const SortOption = createSortOption(
+  () => t('talk-plugin-sort-most-downvoted.label'),
+  { sortBy: 'DOWNVOTES', sortOrder: 'DESC' }
+);
+
+/**
+ * This plugin depends on talk-plugin-viewing-options.
+ */
+
+export default {
+  translations,
+  slots: {
+    viewingOptionsSort: [SortOption],
+  },
+};
diff --git a/plugins/talk-plugin-sort-most-downvoted/client/translations.yml b/plugins/talk-plugin-sort-most-downvoted/client/translations.yml
new file mode 100644
index 000000000..3bff2eed7
--- /dev/null
+++ b/plugins/talk-plugin-sort-most-downvoted/client/translations.yml
@@ -0,0 +1,3 @@
+en:
+  talk-plugin-sort-most-downvoted:
+    label: Most downvoted first
diff --git a/plugins/talk-plugin-sort-most-downvoted/index.js b/plugins/talk-plugin-sort-most-downvoted/index.js
new file mode 100644
index 000000000..f053ebf79
--- /dev/null
+++ b/plugins/talk-plugin-sort-most-downvoted/index.js
@@ -0,0 +1 @@
+module.exports = {};
diff --git a/plugins/talk-plugin-sort-most-downvoted/package.json b/plugins/talk-plugin-sort-most-downvoted/package.json
new file mode 100644
index 000000000..5f79e0de9
--- /dev/null
+++ b/plugins/talk-plugin-sort-most-downvoted/package.json
@@ -0,0 +1,9 @@
+{
+  "name": "@coralproject/talk-plugin-sort-most-downvoted",
+  "pluginName": "talk-plugin-sort-most-downvoted",
+  "version": "0.0.1",
+  "description": "Sort by most downvotes",
+  "main": "index.js",
+  "author": "The Coral Project Team <coral@mozillafoundation.org>",
+  "license": "Apache-2.0"
+}
diff --git a/plugins/talk-plugin-sort-most-upvoted/client/.eslintrc.json b/plugins/talk-plugin-sort-most-upvoted/client/.eslintrc.json
new file mode 100644
index 000000000..c8a6db18a
--- /dev/null
+++ b/plugins/talk-plugin-sort-most-upvoted/client/.eslintrc.json
@@ -0,0 +1,3 @@
+{
+  "extends": "@coralproject/eslint-config-talk/client"
+}
diff --git a/plugins/talk-plugin-sort-most-upvoted/client/index.js b/plugins/talk-plugin-sort-most-upvoted/client/index.js
new file mode 100644
index 000000000..26744b6d6
--- /dev/null
+++ b/plugins/talk-plugin-sort-most-upvoted/client/index.js
@@ -0,0 +1,19 @@
+import translations from './translations.yml';
+import { createSortOption } from 'talk-plugin-viewing-options/client/api/factories';
+import { t } from 'plugin-api/beta/client/services';
+
+const SortOption = createSortOption(
+  () => t('talk-plugin-sort-most-upvoted.label'),
+  { sortBy: 'UPVOTES', sortOrder: 'DESC' }
+);
+
+/**
+ * This plugin depends on talk-plugin-viewing-options.
+ */
+
+export default {
+  translations,
+  slots: {
+    viewingOptionsSort: [SortOption],
+  },
+};
diff --git a/plugins/talk-plugin-sort-most-upvoted/client/translations.yml b/plugins/talk-plugin-sort-most-upvoted/client/translations.yml
new file mode 100644
index 000000000..7b3c7c29f
--- /dev/null
+++ b/plugins/talk-plugin-sort-most-upvoted/client/translations.yml
@@ -0,0 +1,3 @@
+en:
+  talk-plugin-sort-most-upvoted:
+    label: Most upvoted first
diff --git a/plugins/talk-plugin-sort-most-upvoted/index.js b/plugins/talk-plugin-sort-most-upvoted/index.js
new file mode 100644
index 000000000..f053ebf79
--- /dev/null
+++ b/plugins/talk-plugin-sort-most-upvoted/index.js
@@ -0,0 +1 @@
+module.exports = {};
diff --git a/plugins/talk-plugin-sort-most-upvoted/package.json b/plugins/talk-plugin-sort-most-upvoted/package.json
new file mode 100644
index 000000000..221e22c22
--- /dev/null
+++ b/plugins/talk-plugin-sort-most-upvoted/package.json
@@ -0,0 +1,9 @@
+{
+  "name": "@coralproject/talk-plugin-sort-most-upvoted",
+  "pluginName": "talk-plugin-sort-most-upvoted",
+  "version": "0.0.1",
+  "description": "Sort by most upvotes",
+  "main": "index.js",
+  "author": "The Coral Project Team <coral@mozillafoundation.org>",
+  "license": "Apache-2.0"
+}
diff --git a/plugins/talk-plugin-upvote/client/.eslintrc.json b/plugins/talk-plugin-upvote/client/.eslintrc.json
new file mode 100644
index 000000000..9fe56bd14
--- /dev/null
+++ b/plugins/talk-plugin-upvote/client/.eslintrc.json
@@ -0,0 +1,23 @@
+{
+  "env": {
+    "browser": true,
+    "es6": true,
+    "mocha": true
+  },
+  "parserOptions": {
+    "sourceType": "module",
+    "ecmaFeatures": {
+      "experimentalObjectRestSpread": true,
+      "jsx": true
+    }
+  },
+  "parser": "babel-eslint",
+  "plugins": [
+    "react"
+  ],
+  "rules": {
+    "react/jsx-uses-react": "error",
+    "react/jsx-uses-vars": "error",
+    "no-console": ["warn", { "allow": ["warn", "error"] }]
+  }
+}
diff --git a/plugins/talk-plugin-upvote/client/components/Icon.js b/plugins/talk-plugin-upvote/client/components/Icon.js
new file mode 100644
index 000000000..1b34c40cd
--- /dev/null
+++ b/plugins/talk-plugin-upvote/client/components/Icon.js
@@ -0,0 +1,7 @@
+import React from 'react';
+import cn from 'classnames';
+
+// @TODO change icon when we deprecate FA
+export default ({ className }) => (
+  <i className={cn('fa', 'fa-arrow-circle-up', className)} aria-hidden="true" />
+);
diff --git a/plugins/talk-plugin-upvote/client/components/UpvoteButton.css b/plugins/talk-plugin-upvote/client/components/UpvoteButton.css
new file mode 100644
index 000000000..56caa60b1
--- /dev/null
+++ b/plugins/talk-plugin-upvote/client/components/UpvoteButton.css
@@ -0,0 +1,39 @@
+.container {
+  display: inline-block;
+}
+
+.button {
+  color: #2a2a2a;
+  margin: 5px 10px 5px 0px;
+  background: none;
+  padding: 0px;
+  border: none;
+  font-size: inherit;
+  vertical-align: middle;
+
+  &:hover {
+    color: #767676;
+    cursor: pointer;
+  }
+
+  &.upvoted {
+    color: #008000;
+
+    &:hover {
+      color: #66b266;
+      cursor: pointer;
+    }
+  }
+}
+
+.icon {
+  font-size: 12px;
+  padding: 0 3px;
+}
+
+@media (max-width: 425px) {
+  .label {
+    display: none;
+  }
+}
+
diff --git a/plugins/talk-plugin-upvote/client/components/UpvoteButton.js b/plugins/talk-plugin-upvote/client/components/UpvoteButton.js
new file mode 100644
index 000000000..c0db1fe01
--- /dev/null
+++ b/plugins/talk-plugin-upvote/client/components/UpvoteButton.js
@@ -0,0 +1,54 @@
+import React from 'react';
+import Icon from './Icon';
+import styles from './UpvoteButton.css';
+import { withReaction } from 'plugin-api/beta/client/hocs';
+import cn from 'classnames';
+
+const plugin = 'talk-plugin-upvote';
+
+class UpvoteButton extends React.Component {
+  handleClick = () => {
+    const {
+      postReaction,
+      deleteReaction,
+      showSignInDialog,
+      alreadyReacted,
+      user,
+    } = this.props;
+
+    // If the current user does not exist, trigger sign in dialog.
+    if (!user) {
+      showSignInDialog();
+      return;
+    }
+
+    if (alreadyReacted) {
+      deleteReaction();
+    } else {
+      postReaction();
+    }
+  };
+
+  render() {
+    const { count, alreadyReacted } = this.props;
+    return (
+      <div className={cn(styles.container, `${plugin}-container`)}>
+        <button
+          className={cn(
+            styles.button,
+            {
+              [`${styles.upvoted} talk-plugin-upvote-upvoted`]: alreadyReacted,
+            },
+            `${plugin}-button`
+          )}
+          onClick={this.handleClick}
+        >
+          <Icon className={cn(styles.icon, `${plugin}-icon`)} />
+          <span className={cn(`${plugin}-count`)}>{count > 0 && count}</span>
+        </button>
+      </div>
+    );
+  }
+}
+
+export default withReaction('upvote')(UpvoteButton);
diff --git a/plugins/talk-plugin-upvote/client/index.js b/plugins/talk-plugin-upvote/client/index.js
new file mode 100644
index 000000000..fd81298da
--- /dev/null
+++ b/plugins/talk-plugin-upvote/client/index.js
@@ -0,0 +1,7 @@
+import UpvoteButton from './components/UpvoteButton';
+
+export default {
+  slots: {
+    commentReactions: [UpvoteButton],
+  },
+};
diff --git a/plugins/talk-plugin-upvote/index.js b/plugins/talk-plugin-upvote/index.js
new file mode 100644
index 000000000..119537ab3
--- /dev/null
+++ b/plugins/talk-plugin-upvote/index.js
@@ -0,0 +1,2 @@
+const { getReactionConfig } = require('../../plugin-api/beta/server');
+module.exports = getReactionConfig('upvote');
diff --git a/plugins/talk-plugin-upvote/package.json b/plugins/talk-plugin-upvote/package.json
new file mode 100644
index 000000000..bf32d911a
--- /dev/null
+++ b/plugins/talk-plugin-upvote/package.json
@@ -0,0 +1,9 @@
+{
+  "name": "@coralproject/talk-plugin-upvote",
+  "pluginName": "talk-plugin-upvote",
+  "version": "0.0.1",
+  "description": "Upvote comments",
+  "main": "index.js",
+  "author": "The Coral Project Team <coral@mozillafoundation.org>",
+  "license": "Apache-2.0"
+}
diff --git a/routes/index.js b/routes/index.js
index 143ceefd8..489a5e8b5 100644
--- a/routes/index.js
+++ b/routes/index.js
@@ -13,6 +13,7 @@ const staticMiddleware = require('express-static-gzip');
 const { DISABLE_STATIC_SERVER } = require('../config');
 const { passport } = require('../services/passport');
 const { MOUNT_PATH } = require('../url');
+const url = require('url');
 const context = require('../middleware/context');
 
 const router = express.Router();
@@ -31,8 +32,8 @@ if (!DISABLE_STATIC_SERVER) {
   /**
    * Redirect old embed calls.
    */
-  const oldEmbed = path.resolve(MOUNT_PATH, 'embed.js');
-  const newEmbed = path.resolve(MOUNT_PATH, 'static/embed.js');
+  const oldEmbed = url.resolve(MOUNT_PATH, 'embed.js');
+  const newEmbed = url.resolve(MOUNT_PATH, 'static/embed.js');
   router.get('/embed.js', (req, res) => {
     console.warn(
       `deprecation warning: ${oldEmbed} will be phased out soon, please replace calls from ${oldEmbed} to ${newEmbed}`
@@ -132,9 +133,9 @@ if (process.env.NODE_ENV !== 'production') {
   router.get('/', async (req, res, next) => {
     try {
       await SetupService.isAvailable();
-      return res.redirect('/admin/install');
+      return res.redirect(url.resolve(MOUNT_PATH, 'admin/install'));
     } catch (e) {
-      return res.redirect('/admin');
+      return res.redirect(url.resolve(MOUNT_PATH, 'admin'));
     }
   });
 }