Dafny vs OpenJML

Dafny

6.4 #18 in Formal Verification Tools

About Dafny

OpenJML

5.9 #26 in Formal Verification Tools

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

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