Dafny vs OpenJML

Dafny

6.8 #11 in Formal Verification Tools

About Dafny

OpenJML

6.1 #21 in Formal Verification Tools

About OpenJML
DafnyOpenJML
Free planNoNo
Free trialNoNo
Paid from——
Open sourceNoNo
PlatformsLinux, macOS, self-hosted, WindowsWindows, macOS, Linux
Free planYes—
Verification methoddeductivedeductive
Supported formalismscontractscontracts
CounterexamplesYesYes
Input languagesDafnyJava and JML
Deploymentself-hostedself-hosted

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