Foxit Reader 4.2.0.0928 ((free)) -

For pure reading and basic annotation on low-end hardware, the legacy build is objectively faster.

Enhanced to offer better protection when opening suspicious documents by disabling certain executable functions. foxit-reader.soft112.com Critical Bug Fixes Foxit Reader 4.2.0.0928

You cannot discuss legacy software without addressing security. It contains unpatched vulnerabilities (CVEs) from 2011–2015. For pure reading and basic annotation on low-end