Allowing 32-bit XP to recognize more than 4GB of RAM (up to 64GB or 128GB depending on the patch).

If you are looking at a specific report for a "Modern XP" build, it likely features:

Several enthusiasts released "2021 Editions" on platforms like Internet Archive that bundle the original SP3 with every security patch released up until the final POSReady 2009 updates in 2019.

Reports titled or released around generally refer to unofficial "slipstreamed" builds or community update packs designed to make the aging OS usable on modern hardware or for retro-gaming enthusiasts. Key Highlights from 2021 Reports