[2][3][4] Introduced in 1999 and based on the design of the Pipistrel Sinus, the Virus has been produced in a number of variants with different engines, wingspans, and undercarriage configurations.

The Virus is a high-wing, cantilever monoplane of pod-and-boom configuration with a T-tail and air brakes.

[7] Aviation journalist Paul Bertorelli has criticized the aircraft's design for lack of cabin occupant crashworthiness.

[10] The SW 121 is powered by a Rotax 912 S3 and is designed to meet EASA requirements for a Light Sports Aeroplane.

The new variant, also EASA CS-LSA type-certified, features new Garmin G3X Touch touch-screen avionics and a haptic stall warning system, among other equipment.

[18][19][20] The two-seat Pipistrel Virus SW 80 aircraft, known as the Garud after a bird in Hindu mythology, would be used for training of Flight Safety and Air Wing Cadets.