diff --git a/client/modules/IDE/actions/project.js b/client/modules/IDE/actions/project.js
index 2e2bca0b..9055d484 100644
--- a/client/modules/IDE/actions/project.js
+++ b/client/modules/IDE/actions/project.js
@@ -155,18 +155,20 @@ export function saveProject(selectedFile = null, autosave = false) {
           if (!autosave) {
             if (state.ide.justOpenedProject && state.preferences.autosave) {
               dispatch(showToast(5500));
-              dispatch(setToastText('Project saved.'));
+              dispatch(setToastText('Sketch saved.'));
               setTimeout(() => dispatch(setToastText('Autosave enabled.')), 1500);
               dispatch(resetJustOpenedProject());
             } else {
               dispatch(showToast(1500));
-              dispatch(setToastText('Project saved.'));
+              dispatch(setToastText('Sketch saved.'));
             }
           }
         })
         .catch((error) => {
           const { response } = error;
           dispatch(endSavingProject());
+          dispatch(setToastText('Failed to save sketch.'));
+          dispatch(showToast(1500));
           if (response.status === 403) {
             dispatch(showErrorModal('staleSession'));
           } else if (response.status === 409) {
@@ -195,18 +197,20 @@ export function saveProject(selectedFile = null, autosave = false) {
         if (!autosave) {
           if (state.preferences.autosave) {
             dispatch(showToast(5500));
-            dispatch(setToastText('Project saved.'));
+            dispatch(setToastText('Sketch saved.'));
             setTimeout(() => dispatch(setToastText('Autosave enabled.')), 1500);
             dispatch(resetJustOpenedProject());
           } else {
             dispatch(showToast(1500));
-            dispatch(setToastText('Project saved.'));
+            dispatch(setToastText('Sketch saved.'));
           }
         }
       })
       .catch((error) => {
         const { response } = error;
         dispatch(endSavingProject());
+        dispatch(setToastText('Failed to save sketch.'));
+        dispatch(showToast(1500));
         if (response.status === 403) {
           dispatch(showErrorModal('staleSession'));
         } else {
diff --git a/client/modules/IDE/components/PreviewFrame.jsx b/client/modules/IDE/components/PreviewFrame.jsx
index 9f429546..3b193a8f 100644
--- a/client/modules/IDE/components/PreviewFrame.jsx
+++ b/client/modules/IDE/components/PreviewFrame.jsx
@@ -237,16 +237,18 @@ class PreviewFrame extends React.Component {
     jsFileStrings.forEach((jsFileString) => {
       if (jsFileString.match(MEDIA_FILE_QUOTED_REGEX)) {
         const filePath = jsFileString.substr(1, jsFileString.length - 2);
+        const quoteCharacter = jsFileString.substr(0, 1);
         const resolvedFile = resolvePathToFile(filePath, files);
+
         if (resolvedFile) {
           if (resolvedFile.url) {
-            newContent = newContent.replace(filePath, resolvedFile.url);
+            newContent = newContent.replace(jsFileString, quoteCharacter + resolvedFile.url + quoteCharacter);
           } else if (resolvedFile.name.match(PLAINTEXT_FILE_REGEX)) {
             // could also pull file from API instead of using bloburl
             const blobURL = getBlobUrl(resolvedFile);
             this.props.setBlobUrl(resolvedFile, blobURL);
-            const filePathRegex = new RegExp(filePath, 'gi');
-            newContent = newContent.replace(filePathRegex, blobURL);
+
+            newContent = newContent.replace(jsFileString, quoteCharacter + blobURL + quoteCharacter);
           }
         }
       }
@@ -262,10 +264,11 @@ class PreviewFrame extends React.Component {
     cssFileStrings.forEach((cssFileString) => {
       if (cssFileString.match(MEDIA_FILE_QUOTED_REGEX)) {
         const filePath = cssFileString.substr(1, cssFileString.length - 2);
+        const quoteCharacter = cssFileString.substr(0, 1);
         const resolvedFile = resolvePathToFile(filePath, files);
         if (resolvedFile) {
           if (resolvedFile.url) {
-            newContent = newContent.replace(filePath, resolvedFile.url);
+            newContent = newContent.replace(cssFileString, quoteCharacter + resolvedFile.url + quoteCharacter);
           }
         }
       }
diff --git a/client/modules/IDE/pages/IDEView.jsx b/client/modules/IDE/pages/IDEView.jsx
index 9ff8351d..fbb3dafc 100644
--- a/client/modules/IDE/pages/IDEView.jsx
+++ b/client/modules/IDE/pages/IDEView.jsx
@@ -34,6 +34,15 @@ import AddToCollectionList from '../components/AddToCollectionList';
 import Feedback from '../components/Feedback';
 import { CollectionSearchbar } from '../components/Searchbar';
 
+function getTitle(props) {
+  const { id } = props.project;
+  return id ? `p5.js Web Editor | ${props.project.name}` : 'p5.js Web Editor';
+}
+
+function isUserOwner(props) {
+  return props.project.owner && props.project.owner.id === props.user.id;
+}
+
 class IDEView extends React.Component {
   constructor(props) {
     super(props);
@@ -92,7 +101,7 @@ class IDEView extends React.Component {
   }
 
   componentDidUpdate(prevProps) {
-    if (this.isUserOwner() && this.props.project.id) {
+    if (isUserOwner(this.props) && this.props.project.id) {
       if (this.props.preferences.autosave && this.props.ide.unsavedChanges && !this.props.ide.justOpenedProject) {
         if (
           this.props.selectedFile.name === prevProps.selectedFile.name &&
@@ -123,21 +132,12 @@ class IDEView extends React.Component {
     this.autosaveInterval = null;
   }
 
-  getTitle = () => {
-    const { id } = this.props.project;
-    return id ? `p5.js Web Editor | ${this.props.project.name}` : 'p5.js Web Editor';
-  }
-
-  isUserOwner() {
-    return this.props.project.owner && this.props.project.owner.id === this.props.user.id;
-  }
-
   handleGlobalKeydown(e) {
     // 83 === s
     if (e.keyCode === 83 && ((e.metaKey && this.isMac) || (e.ctrlKey && !this.isMac))) {
       e.preventDefault();
       e.stopPropagation();
-      if (this.isUserOwner() || (this.props.user.authenticated && !this.props.project.owner)) {
+      if (isUserOwner(this.props) || (this.props.user.authenticated && !this.props.project.owner)) {
         this.props.saveProject(this.cmController.getContent());
       } else if (this.props.user.authenticated) {
         this.props.cloneProject();
@@ -208,7 +208,7 @@ class IDEView extends React.Component {
     return (
       <div className="ide">
         <Helmet>
-          <title>{this.getTitle()}</title>
+          <title>{getTitle(this.props)}</title>
         </Helmet>
         {this.props.toast.isVisible && <Toast />}
         <Nav
@@ -313,7 +313,7 @@ class IDEView extends React.Component {
                   isExpanded={this.props.ide.sidebarIsExpanded}
                   expandSidebar={this.props.expandSidebar}
                   collapseSidebar={this.props.collapseSidebar}
-                  isUserOwner={this.isUserOwner()}
+                  isUserOwner={isUserOwner(this.props)}
                   clearConsole={this.props.clearConsole}
                   consoleEvents={this.props.console}
                   showRuntimeErrorWarning={this.props.showRuntimeErrorWarning}
diff --git a/client/modules/IDE/selectors/collections.js b/client/modules/IDE/selectors/collections.js
index f212103a..dd052aab 100644
--- a/client/modules/IDE/selectors/collections.js
+++ b/client/modules/IDE/selectors/collections.js
@@ -37,6 +37,11 @@ const getSortedCollections = createSelector(
         return orderBy(collections, 'name', 'desc');
       }
       return orderBy(collections, 'name', 'asc');
+    } else if (field === 'numItems') {
+      if (direction === DIRECTION.DESC) {
+        return orderBy(collections, 'items.length', 'desc');
+      }
+      return orderBy(collections, 'items.length', 'asc');
     }
     const sortedCollections = [...collections].sort((a, b) => {
       const result =
diff --git a/developer_docs/installation.md b/developer_docs/installation.md
index 047f21d1..fce3e44f 100644
--- a/developer_docs/installation.md
+++ b/developer_docs/installation.md
@@ -69,9 +69,8 @@ Note that this is optional, unless you are working on the part of the applicatio
 If your S3 bucket is in the US East (N Virginia) region (us-east-1), you'll
 need to set a custom URL base for it, because it does not follow the standard
 naming pattern as the rest of the regions. Instead, add the following to your
-environment/.env file:
-
-`S3_BUCKET_URL_BASE=https://s3.amazonaws.com`
+environment/.env file, changing `BUCKET_NAME` to your bucket name. This is necessary because this override is currently treated as the full path to the bucket rather than as a proper base url:
+`S3_BUCKET_URL_BASE=https://s3.amazonaws.com/{BUCKET_NAME}/`
 
 If you've configured your S3 bucket and DNS records to use a custom domain
 name, you can also set it using this variable. I.e.:
diff --git a/server/controllers/embed.controller.js b/server/controllers/embed.controller.js
index 67edcd04..2d8bef6a 100644
--- a/server/controllers/embed.controller.js
+++ b/server/controllers/embed.controller.js
@@ -34,6 +34,7 @@ export function serveProject(req, res) {
         resolveScripts(sketchDoc, files);
         resolveStyles(sketchDoc, files);
 
+        res.setHeader('Cache-Control', 'public, max-age=0');
         res.send(serializeDocument(sketchDoc));
       });
     });
diff --git a/server/scripts/examples.js b/server/scripts/examples.js
index 7e11fe3d..e905fca3 100644
--- a/server/scripts/examples.js
+++ b/server/scripts/examples.js
@@ -73,7 +73,7 @@ function getCategories() {
 function getSketchesInCategories(categories) {
   return Q.all(categories.map((category) => {
     const options = {
-      url: `${category.url.replace('?ref=master', '')}?client_id=${clientId}&client_secret=${clientSecret}`,
+      url: `${category.url.replace('?ref=main', '')}?client_id=${clientId}&client_secret=${clientSecret}`,
       method: 'GET',
       headers,
       json: true
@@ -107,7 +107,7 @@ function getSketchesInCategories(categories) {
 function getSketchContent(projectsInAllCategories) {
   return Q.all(projectsInAllCategories.map(projectsInOneCategory => Q.all(projectsInOneCategory.map((project) => {
     const options = {
-      url: `${project.sketchUrl.replace('?ref=master', '')}?client_id=${clientId}&client_secret=${clientSecret}`,
+      url: `${project.sketchUrl.replace('?ref=main', '')}?client_id=${clientId}&client_secret=${clientSecret}`,
       method: 'GET',
       headers
     };
@@ -264,7 +264,7 @@ function createProjectsInP5user(projectsInAllCategories) {
               const fileID = objectID().toHexString();
               newProject.files.push({
                 name: assetName,
-                url: `https://cdn.jsdelivr.net/gh/processing/p5.js-website@master/src/data/examples/assets/${assetName}`,
+                url: `https://cdn.jsdelivr.net/gh/processing/p5.js-website@main/src/data/examples/assets/${assetName}`,
                 id: fileID,
                 _id: fileID,
                 children: [],