This tilt manifests in a variety of ways. For example: making it harder for a user to download and use a different browser, ignoring or resetting a user’s default browser preference, restricting capabilities to the first-party browser, or requiring the use of the first-party browser engine for third-party browsers.
For years, Mozilla has engaged in dialog with platform vendors in an effort to address these issues. With renewed public attention and an evolving regulatory environment, we think it’s time to publish these concerns using the same transparent process and tools we use to develop positions on emerging technical standards. So today we’re publishing a new issue tracker where we intend to document the ways in which platforms put Firefox at a disadvantage and engage with the vendors of those platforms to resolve them.↫ The official Mozilla blog