ACL2 vs TLA+

ACL2

6.0 #2 in Formal Verification Tools

About ACL2

TLA+

5.1 #27 in Formal Verification Tools

About TLA+
ACL2TLA+
Free planNoNo
Free trialNoNo
Paid from——
Open sourceNoNo
PlatformsLinux, macOS, self-hosted, WindowsWindows, macOS, Linux
Free planYes—
Verification methoddeductivehybrid
Supported formalismstheorem-provinginvariants
CounterexamplesYesYes
Proof artifactsYes—
Input languagesACL2 logic and a subset of applicative Common LispTLA+ and PlusCal
Deploymentself-hostedboth

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