1. COOL- the coalgebraic ontology logic reasoner. cal8.cs.fau.de/redmine/projects/cool. COOL- the coalgebraic ontology logic reasoner. cal8.cs.fau.de/redmine/projects/cool.
2. Coq theorem prover. coq.inria.fr. Coq theorem prover. coq.inria.fr.
3. DLVSYSTEM. www.dlvsystem.com. DLVSYSTEM. www.dlvsystem.com.
4. The leanCoP theorem prover. www.leancop.de. The leanCoP theorem prover. www.leancop.de.
5. PDQ. Available at www.cs.ox.ac.uk/projects/pdq/home.html. PDQ. Available at www.cs.ox.ac.uk/projects/pdq/home.html.