Where an application becomes moot due to supervening events (such as a superior court judgment that resolves the underlying controversy), the court has discretion to permit withdrawal without traversing the academic merits. However, where a party seeks to withdraw on the eve of a hearing after the matter has been set down and the opposing party has incurred costs in preparation, including briefing counsel, the withdrawing party should bear the wasted costs occasioned by the set-down and appearance, even though the matter became moot through no fault of either party. The general principle that a party whose conduct causes another to incur wasted costs should bear such costs applies, and fairness requires compensating the prejudiced party to the limited extent of counsel's fees for preparation and appearance.