Open source libraries and utilities to support using digital signatures for Amateur
radio QSL information. It can be used to digitally sign and upload QSOs to the ARRL's Logbook of the World (LoTW) online service and to manage the Callsign Certificates used when digitally signing. TQSL accepts QSOs in a log file whose format is either ADIF or Cabrillo, which many logging applications can create.
