1. Boogie program prover.
https://github.com/boogie-org/boogie
2. CBMC model checker.
https://github.com/diffblue/cbmc
3. CompCert project.
http://compcert.inria.fr
4. Coq theorem prover.
https://github.com/coq/coq
5. CVC4 decision procedure.
http://cvc4.cs.stanford.edu