: This is considered the "last good version" for XP by many users because it offers the most modern feature set (like basic highlighting and commenting) while maintaining system stability.
Using any internet-connected application on Windows XP today is risky. For PDFs specifically: adobe reader windows xp
: Known for being faster than Adobe, though newer versions can be "bloated". Older builds like version 2.0 or 3.0 are ideal for XP. : This is considered the "last good version"