Chromium

Basic Information
Release Year	2-Sep-2008
Product Type
In Production	Yes
Official Website	https://chromium.org/

Chromium is a free and open-source web browser developed by and primarily maintained by Google.^[1] Several major web browsers use Chromium as the base of their software, including Google Chrome,^[1] Microsoft Edge,^[2] Opera/Opera GX,^[3] Brave,^[4] and others.

Manifest V3 is an update to the manifest structure used by browser extensions across the majority of the browser market, presented as an upgrade in security, privacy, and performance of these extensions.^[5][6] The changes restrict the access browser extensions can have, thereby enhancing security by preventing them from loading remote resources immediately or significantly altering rendered content. These limitations effectively render the browser market's most effective ad-blockers ineffective.^[7] Despite the developers' efforts to bypass the issue using workarounds and updated versions of Manifest V3, the software's previous efficiency has not been fully restored. For example, blocked domains cannot be updated as conveniently.^[8] This manifest change is supported by leading Chromium-based browsers, making it challenging for other browsers to match previous ad-blocking capabilities without committing to retaining Manifest V2 (such as Firefox, which also utilizes Chromium-sourced manifests) or implementing their own ad-blocking solutions of varying^[9]) or utilizing their own ad-blocking solutions^[10] of varied effectiveness.^[11]

Almost as soon as a design draft for Manifest V3 was made public, on November 9th 2018^[12], developers disapproved of the changes proposed by it, including the developers of privacy and security-focused tools such as NoScript, AdGuard, uMatrix, and uBlock Origin.^[13] On January 22, 2019, in response to the design draft, the developer for uBlock Origin and uMatrix would go on to write, "if this (quite limited) [...] API ends up being the only way content blockers can accomplish their duty, this essentially means that content blockers I have maintained for years, uBlock Origin ("uBO") and uMatrix, can no longer exist." And also, "[...] deprecating the blocking ability of the [...] API will essentially decrease the level of user agency in Chromium, to the benefit of web sites which obviously would be happy to have the last word in what resources their page can fetch/execute/render."^[14] A developer for AdGuard would second his points. A Chromium developer did not immediately answer these points, but instead directed the discussion to take place over private emails rather than the bug tracker.^[15]

Chromium's code is published under the 3-clause BSD license.^[16]