This is a core script in KiriKiri-based games used to override or "patch" original game files without altering the main .xp3 archives. It allows developers and fan-translators to inject custom code, UI changes, or translated text.
zeas2/Kirikiroid2_patch: Patch Library for Kirikiroid2 - GitHub patchtjs xp3filtertjs exclusive
XP3Filter.js seems to relate to filtering or manipulating data or content, possibly specifically in the context of game development or modding, given the "XP3" designation. In game development, particularly with games that use the Source engine (like many Valve games), XP3 files are used for packaging game assets. An XP3 filter could be used to decode, manipulate, or otherwise process these files. The ".js" indicates it's a JavaScript implementation, suggesting it's used in web-based tools or Node.js applications for asset manipulation. This is a core script in KiriKiri-based games