ACL2 vs Why3

ACL2

6.6 #9 in Formal Verification Tools

About ACL2

Why3

5.9 #29 in Formal Verification Tools

About Why3
ACL2Why3
Free planNoNo
Free trialNoNo
Paid from——
Open sourceNoNo
PlatformsLinux, macOS, self-hosted, WindowsWeb, Linux, Windows
Free planYes—
Verification methoddeductivedeductive
Supported formalismstheorem-provingcontracts
CounterexamplesYesYes
Proof artifactsYes—
Input languagesACL2 logic and a subset of applicative Common LispWhyML, micro-C, micro-Python, MLCFG, Coma
Deploymentself-hostedboth

Both are listed in Best Formal Verification Tools. On The Geeks Club, ACL2 scores higher on our published basis.