General
Support userscript editing at vscode.dev if the Tampermonkey Editors extension is installed
Allow cloud backups to be downloaded
Fix the active script count when an embedded frame is removed
Fix automatic detection mode of the option 'Add GM functions to this or window'
Fix disappearing 'Yes' value of the 'Modify existing content security policy headers' option
Fix menu command listeners sometimes being executed multiple times
Fix GM_deleteValue to really delete values also in background
Make the storage editor show undefined values as well

UI
Introducing Tam, your helpful assistant for getting started
Search editor as you type

Sync
Make TamperDAV script change detection work regardless of boot order
When using WebDAV, add a trailing slash notation to collection names as suggested by the spec
Fix issues regarding enabling and disabling sync

Locales
Localize extension name and description
Update Italian translation | thanks to bovirus
Update Japanese translation | thanks to shirayuki
Update Chinese (simplified) translation | thanks to gin3715
Update Russian translation | thanks to Tyemak
Update Danish translation | thanks to jhertel

Experimental
Add experimental GM_info.userAgentData with all properties of NavigatorUAData and some "high entropy" values

General
Fix GM_unregisterMenuCommand
Fix GM.saveTab
Make @sandbox always default to raw
Make console methods enumerable again
Disable wrappedJSObject compatibility option by default

Firefox
Fix variable access via unsafeWindow in JavaScript sandbox mode
Fix instant injection in combination with document-start scripts
Fix communication with external pages
Fix some CSP issues by injecting the script code earlier

Sync
Fix an issue that script updates were disabled on sync triggered change imports

Firefox:
Use userScript API to execute userscripts
Add container ID to GM_info
Fix script counter at file URLs
Fix sandbox window to have Object.prototype properties
Make GM_xhr multi-account container aware

General:
Experimental @sandbox support with possible values 'raw', 'JavaScript' and 'DOM'
Add an option to configure available sandbox modes
Remove document.addEventListener('DOMContentLoaded', ...) delayed event dispatching for document-start scripts executed later than the event
Remove toSource object prototype compat option
Allow GM_xhr streams to be canceled
Add GM_xhr.upload.onprogress support
Add some more entries to the download file extension whitelist
Add GM_download.details.conflictAction (works only in browser API mode)
Fix @resource SVG handling
Add some more editor shortcuts

UI:
Allow script tabs to be closed via middle mouse click
Add a close button to the header of some more dialogs
Fix script toggle element if darker theme is enabled

Locales:
Add Macedonian translation | thanks to EntityPlantt
Add Hellenic (Greek) translation | thanks to panos78
Update Chinese (simplified) translation | thanks to iskandarma
Update Portuguese-Brazil translation | thanks to DavidBrazSan
Update Russian translation | thanks to vanja-san

Sync:
Add an access token revoke button to some more cloud storage types
Note: make sure to sign out from the service first if you want to login with another account.
Show script sync log messages at the settings page
Dropbox: avoid upload of identical content

General:
Fix issues with heavily increased page loading time caused by some scripts or @requires

UI:
Allow drag and drop inside the editor again

Locales:
Update Chinese (traditional) translation | thanks to SiderealArt
Update Italian translation | thanks to bovirus
Update Danish translation | thanks to will2022

General:
Sandbox improvements
External @require and @resource content is not updated by default anymore unless the script was updated
Improved compatibility for userstyles installed as userscript
Add an option to control whether to bind GM API functions to the userscript's execution context and sandbox window (and do it by default only if necessary)
Treat @include a little bit more like @match if :// is present and add an option to control @include's behavior
Fix encoding of userscript file and URL imports

Firefox:
Fix iframe issues

UI:
Show script and external resources size in dashboard
Show last updated time as relative time if within 4 weeks or as absolute date otherwise
Fix darker theme quirk
Fix favicons with transparent background
Improve editor menu if advanced editor is disabled

Firefox:
Add GM_notification.highlight support
Fix 'promise out of scope' warning

Locales:
Update Turkish translation | thanks to Tmp341
Update Japanese translation | thanks to shirayuki
Update Portuguese-Brazil translation | thanks to igorruckert
Update Chinese (simplified) translation | thanks to xiaopangju
Update Chinese (simplified) translation | thanks to dnknn
Update Hindi translation | thanks to Yash-Singh1
Update French translation | thanks to omerien
Update Italian translation | thanks to bovirus
Update Russian translation | thanks to wvxwxvw
Update Chinese (traditional) translation | thanks to ndbiaw and SiderealArt

General:
Allow userscript installation via drag and drop to options page also in case local file access is disabled
Allow GM_getValue to return undefined as value
Improve JavaScript scriptlet support via @unwrap tag
Sandbox improvements
Use up to ES2022 for linting if supported by the browser
Update ESLint
Add a global and a per script setting to choose whether to run in incognito tabs
Make trash configurable (on/off/session only)
Fix issues caused by extremely delayed setTimeout(..., 0) calls
Add MouseEvent/KeyboardEvent argument to GM_registerMenuCommand callbacks
Add a focus method to the return value of GM_openInTab
GM_xmlhttpRequest.responseType 'stream' support

UI:
Decrease extension size by removing jQuery dependency
Shift key + mouse click based multi select
Validate @grant as well as header tags in general
Fix storage 'reload' button and add 'reset'
Fix ESLint to allow top-level await
Warn on userscript header entries that are not prefixed by exactly one space
Show localized userscript name and description if available where possible
Dark mode improvements
Prefer an explicit set @name:en over @name
Update page title if script is renamed by save
Keep CRLF line endings on edit

Sync:
WebDAV improvements
Fix TamperDAV double sync issue
Add a button to force a sync
Fix unnecessary repeated exports
Trigger sync on move to trash

General:
Fix script externals import issues
Fix import from zip files with folders
Use https for all links to tampermonkey.net
Fix GM_xhr.responseType 'document' support
Allow script editing via external editor by using TamperDAV
Reduce memory footprint (by doing less caching)
Add GitLab subgroup support
Add several .com.* 2nd level domains
Sync:
Increase WebDAV protocol compatibility
WebDAV based cross-browser sync (beta; tested with OwnCloud and TamperDAV)
UI:
Minor layout refresh
Fix blurry icons
Avoid action menu flicker on GM_registerMenuCommand usage
Update dark theme | thanks to narcolepticinsomniac
Add narcolepticinsomniac's dark theme matching editor layout
Make the script filter bar work if its visibility is enforced via Custom CSS

General:
Allow ESLint inline configuration again to make globals definition work
Import and export of external resources (@resource and @require)
Replace zip.js by JSZip
Fix an internal cache related problem which could have caused data-loss
UI:
Invert (and fix) meaning of the case-insensitivity search option
Further search bar improvements
Allow the editor button bar to be restored via Custom CSS
Set ESLint ECMAScript version according to the browser's capabilities
Locales:
Update Portuguese-Brazil locale | thanks to igorruckert
Update Japanese locale | thanks to ScratchBuild
Update Italian locale | thanks to bovirus
Update Chinese (simplified) locale | thanks to efreedev

General:
Switch from JSHint to ESLint 4.19.0
Clean GM_tabs data on tab close
Fix script externals update
Locales:
Add Croatian and Serbian locale | thanks to faultyfuse
Update Italian locale | thanks to bovirus
Add Hindi locale
Update Russian locale | thanks to Dr-Yukon
Update Turkish locale | thanks to ali-demirtas
Update Portuguese-Brazil locale | thanks to igorruckert
UI:
Lint in background for more editor responsiveness
Limit displayed script name length
Update CodeMirror to version 5.35
Rework editor search
Add action menu option to exclude a script from a domain
Remember scroll position on tab switch
Firefox:
Create a new beta channel
Make Instant Injection more reliable
Sync:
Dropbox based cross-browser sync (beta)

UI:
Add a lot of editor commands to the menu

General:
Add .co.th to .tld

Locales:
Update French locale | thanks to zek0faws

UI:
Fix script update setting saving
Fix display of SVG icons
Better @downloadURL none support
Minor script install page fix
Allow script source code to be searched as well
Editor menu
Fixes related to the modified script close icon
Fix script storage editor to not reset to its initial data on every tab selection

General:
Fix an issue which could break page scripts
Avoid update requests to Greasyfork scripts with a pinned version
Fix GM_notification click listener
Fix GM_download progress events
Fix GM_download.abort
Fix issues if GM_openInTab.name= or GM_openInTab.close was used at more than one tab

Locales:
Add Vietnamese | thanks to Connor37
Update Russian locale | thanks to BychekRU and irainman
Update Italian locale | thanks to bovirus
Update Norwegian locale | thanks to LarsSimonsen
Update Czech locale | thanks to engycz
Update Indonesian locale | thanks to DhannyNara
Update Arabic locale | thanks to Alayady
Update Russian locale | thanks to BychekRU

Simple script storage editor
Allow all browsers to use synchronization
Allow script update servers to signal unchanged content
Fix blank action menu issue
Make GM_download support all common details properties at FF >= 52
Experimental: Enable browser sync at FF >= 53
Add GitLab and Bitbucket support
Avoid some 'Unchecked lastError' warnings | thanks to tophf
Add Portuguese locale | thanks to Sara F.
Update Polish locale | thanks to hawkeye116477
Fix issues at some pages
Make sure all config is written before reloading
Fix issues at nightly builds
Add an option to add custom CSS to the Tampermonkey UI
Add an option to disable the update check on a script base
Allow scripts to run at XML pages | thanks to Thom1729 for the slight lead
Fix some sandbox functions (set/clearTimeout/Interval and add/removeEventListener) to properly handle unusual arguments

Use "stickering" to improve the icon visibility at dark themes
Log @require related errors at the page console
Fix some rare internal exceptions
Update Korean locale | thanks to KENNYSOFT
Fix CSP related issues
Add ZenBurn editor theme
Visual bookmark support

Add Korean locale | thanks to KENNYSOFT
Fix GM_notification
Enable webRequest support at Firefox 52+ to fix many GM_xhr related issues (finalUrl, cookies, ...)
Fix missing action menu icon at internal tabs
Make xhr response headers available at readyState 2 and higher
Add time and browser to backup names
Fix relative URL handling
Fix sync issues of script comment properties
Fix doubled include/exclude editor dialogs
Make * include file URIs as well
Update the ES6 script template

Speed up storage writing
Fix extension reload for version 51 and above
Improved script search/filtering at the dashboard

Allow backup and restore with cloud storages (Google Drive, Dropbox, OneDrive)
Update Chinese (traditional) locale | thanks to TobySkarting
Update Czech locale | thanks to d3jv
Remove autodetection of some compatibility options
Update JSHint to 2.9.2

Fix the sandbox on{event} properties
Fix the editor replace code and show which part of the script text is going to be replaced
Update Chinese (simplified) locale | thanks to lychichem
Update saveAs to 1.3.2
Firefox: fix GM_download
Firefox: fix drag and drop script positioning

Fix cancelation of GM_xhr requests (not completely working in fetch mode)
Use a fallback in case the page CSP wasn't relaxed (disabled setting or cached page)
Update Portuguese-Brazil locale | thanks to oliveirafabio
Firefox: make the manifest Firefox 47 compatible