| System | Divisions | Entrants | Affiliation |
|---|---|---|---|
| Darwin CASC-J2 | MIX SAT* EPR | Alexander Fuchs (Peter Baumgartner, Cesare Tinelli) | Universität Koblenz-Landau, Germany |
| DCTP 1.3-EPR | EPR | CASC | CASC-19 EPR winner |
| DCTP 1.31 | MIX SAT EPR | Gernot Stenz (Reinhold Letz) | Technische Universität München |
| DCTP 10.21p | MIX FOF SAT EPR | Gernot Stenz (Reinhold Letz) | |
| Dilemma 0.1 | FOF* | Magnus Björk | Chalmers University of Technology |
| E 0.82 | MIX FOF UEQ | Stephan Schulz | Technische Universität München and IRC/irst |
| EP 0.82 | MIX* FOF* | Stephan Schulz | Technische Universität München and IRC/irst |
| E-SETHEO csp04 | MIX FOF SAT EPR UEQ | Gernot Stenz (Stephan Schulz, Reinhold Letz) | Technische Universität München |
| Gandalf c-2.6-SAT | SAT | CASC | CASC-19 SAT winner |
| Mace2 2.2 | SAT* | William McCune | Argonne National Laboratory |
| Mace4 2004-D | SAT* | William McCune | Argonne National Laboratory |
| Octopus 2004 | MIX* (demo) | Monty Newborn (Zongyan Wang) | McGill University |
| Otter 3.3 | MIX* FOF UEQ | CASC (William McCune) | CASC (Argonne National Laboratory) |
| Paradox 1.0 | SAT* | CASC | CASC-19 SAT winner |
| Paradox 1.1 | SAT* EPR | Koen Claessen (Niklas Sörensson) | Chalmers University of Technology |
| SOS 1.0 | MIX* UEQ | John Slaney (Arnold Binas, David Price) | Australian National University |
| THEO J2004 | MIX* | Monty Newborn | McGill University |
| Vampire 5.0 | FOF | CASC | CASC-19 FOF winner (also CASC-18!) |
| Vampire 6.0 | MIX* | CASC | CASC-19 MIX winner |
| Vampire 7.0 | MIX* FOF* EPR UEQ | Andrei Voronkov (Alexandre Riazanov) | The University of Manchester |
| Waldmeister 702 | UEQ | CASC | CASC-19 UEQ winner (also CASC-18!) |
| Waldmeister 704 | UEQ | Thomas Hillenbrand (Bernd Löchner, Jean-Marie Gaillourdet) | Max-Planck-Institut für Informatik (Technische Universität Kaiserslautern) |