Logica
Babbage
Truth Tables
Boole
Multicolumn Truth Tables
Herbrand
Sentence Analyzer (experimental)
Quine
Equivalence Editor
Stickel
Clausal Form Converter
Wegman
Unifier
Clarke
Logic Grids
Russell
Logic Grids (experimental)
Hilbert
Hilbert-style Proof Editor
Fitch
Fitch-style Proof Editor
Robinson
Resolution Proof Editor