> The BigInt primitive (base number format) in JavaScript allows JavaScript to handle excessively large integers (whole numbers). This primitive is especially useful for specialized scientific applications that need very large yet accurate numbers, but has seen widespread adoption for an as of yet unknown reason as part of web frameworks, causing general web compatibility issues for Pale Moon when scripts expect BigInt support and instead have an error thrown. We have now implemented this primitive for use so we no longer have compatibility issues with these frameworks. It is still unknown why BigInt is in use there and for what.
https://www.palemoon.org/releasenotes.shtml