--- a/devtools/client/aboutdebugging-new/aboutdebugging.css
+++ b/devtools/client/aboutdebugging-new/aboutdebugging.css
@@ -1,15 +1,15 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 @import "resource://devtools/client/themes/variables.css";
 @import "resource://devtools/client/aboutdebugging-new/src/components/App.css";
-@import "resource://devtools/client/aboutdebugging-new/src/components/RuntimesPane.css";
+@import "resource://devtools/client/aboutdebugging-new/src/components/Sidebar.css";
 @import "resource://devtools/client/aboutdebugging-new/src/components/runtime/RuntimeItem.css";
 
 :root {
   --runtime-item-icon-color: var(--grey-30);
   --runtime-item-selected-color: var(--blue-55);
 }
 
 html, body {

--- a/devtools/client/aboutdebugging-new/src/components/App.js
+++ b/devtools/client/aboutdebugging-new/src/components/App.js
@@ -7,34 +7,34 @@
 const { connect } = require("devtools/client/shared/vendor/react-redux");
 const { createFactory, PureComponent } = require("devtools/client/shared/vendor/react");
 const dom = require("devtools/client/shared/vendor/react-dom-factories");
 const PropTypes = require("devtools/client/shared/vendor/react-prop-types");
 
 const Runtime = require("../runtimes/runtime");
 const ThisFirefox = require("../runtimes/this-firefox");
 
-const RuntimesPane = createFactory(require("./RuntimesPane"));
+const Sidebar = createFactory(require("./Sidebar"));
 
 class App extends PureComponent {
   static get propTypes() {
     return {
       selectedRuntime: PropTypes.instanceOf(Runtime),
       thisFirefox: PropTypes.instanceOf(ThisFirefox).isRequired,
     };
   }
 
   render() {
     const { selectedRuntime, thisFirefox } = this.props;
 
     return dom.div(
       {
         className: "app",
       },
-      RuntimesPane({ selectedRuntime, thisFirefox })
+      Sidebar({ selectedRuntime, thisFirefox })
     );
   }
 }
 
 const mapStateToProps = state => {
   return {
     selectedRuntime: state.runtimes.selectedRuntime,
   };

rename from devtools/client/aboutdebugging-new/src/components/RuntimesPane.css
rename to devtools/client/aboutdebugging-new/src/components/Sidebar.css
--- a/devtools/client/aboutdebugging-new/src/components/RuntimesPane.css
+++ b/devtools/client/aboutdebugging-new/src/components/Sidebar.css
@@ -1,8 +1,8 @@
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-.runtimes-pane {
+.sidebar {
   margin-block-start: 70px;
   width: 240px;
 }

rename from devtools/client/aboutdebugging-new/src/components/RuntimesPane.js
rename to devtools/client/aboutdebugging-new/src/components/Sidebar.js
--- a/devtools/client/aboutdebugging-new/src/components/RuntimesPane.js
+++ b/devtools/client/aboutdebugging-new/src/components/Sidebar.js
@@ -8,36 +8,36 @@ const { createFactory, PureComponent } =
 const dom = require("devtools/client/shared/vendor/react-dom-factories");
 const PropTypes = require("devtools/client/shared/vendor/react-prop-types");
 
 const ThisFirefox = require("../runtimes/this-firefox");
 
 const Runtime = require("../runtimes/runtime");
 const RuntimeItem = createFactory(require("./runtime/RuntimeItem"));
 
-class RuntimesPane extends PureComponent {
+class Sidebar extends PureComponent {
   static get propTypes() {
     return {
       selectedRuntime: PropTypes.instanceOf(Runtime),
       thisFirefox: PropTypes.instanceOf(ThisFirefox).isRequired,
     };
   }
 
   render() {
     const { selectedRuntime, thisFirefox } = this.props;
 
     return dom.section(
       {
-        className: "runtimes-pane",
+        className: "sidebar",
       },
       dom.ul(
         {},
         RuntimeItem({
           icon: thisFirefox.getIcon(),
           isSelected: thisFirefox === selectedRuntime,
           name: thisFirefox.getName(),
         })
       )
     );
   }
 }
 
-module.exports = RuntimesPane;
+module.exports = Sidebar;

--- a/devtools/client/aboutdebugging-new/src/components/moz.build
+++ b/devtools/client/aboutdebugging-new/src/components/moz.build
@@ -4,11 +4,11 @@
 
 DIRS += [
     'runtime',
 ]
 
 DevToolsModules(
     'App.css',
     'App.js',
-    'RuntimesPane.css',
-    'RuntimesPane.js'
+    'Sidebar.css',
+    'Sidebar.js'
 )