Manifest V3 usage

Manifest V3 is the replacement API created by Google for third-party Extensions on the Chromium web engine. The announcement was that by the end of 2023, the Chrome Web Store will not allow new Extension updates using Manifest V2.

RetroTxt 5 uses Manifest V3, while earlier editions used Manifest version 2.

The use of service workers that make the source code easier to layout and debug. RetroTxt v5 is now more resilient, and the migration fixed some previously hard-to-trace behavior bugs.
Service workers also mean future features will be simpler to implement and test.
Unfocused tabs can run the RetroTxt process while in the background.
Offers an improved and safer permissions system, which means RetroTxt can work out of the box with less scary-looking permissions requests.

Firefox has limited support for Manifest V3, and there is no timeline for its full implementation.