The Defender program was a starship design project dating from the early years of the New Republic, in which the nascent Republic Engineering Corporation shipbuilding conglomerate developed plans for a "pocket Star Destroyer", a starfighter carrier, and a new snubfighter.
Only the starfighter was developed rapidly, seeing some service in the years after Endor, but while apparently respected and capable, it never seems to have become commonplace; the two capital-ship designs were delayed by Grand Admiral Thrawn's campaigns and Operation Shadow Hand, and would only enter service as part of the larger New Class Modernization Program, in which they became the Nebula-class Star Destroyer and the Defender-class assault carrier, and lent their basic hull designs to the Endurance-class fleet carrier and Majestic-class heavy cruiser.
The Defender program was introduced in the Cracken's Threat Dossier RPG resource, where it was made the precursor of the later New Class project, and the source of two of the four basic capital ship hull forms of that larger project. The additional starfighter design had been created earlier for a RPG campaign, The DarkStryder Campaign; in the Star Wars universe, it was said to have been adapted from an earlier design, and in reality, it was inspired by a late-production set in the Kenner toy line.
The Defender program was introduced in the Cracken's Threat Dossier RPG resource, where it was made the precursor of the later New Class project, and the source of two of the four basic capital ship hull forms of that larger project. The additional starfighter design had been created earlier for a RPG campaign, The DarkStryder Campaign; in the Star Wars universe, it was said to have been adapted from an earlier design, and in reality, it was inspired by a late-production set in the Kenner toy line.