Lufthansa (via Frankfurt/Munich) often offers reliable connections and a strong Star Alliance network for BOS to VIE travelers, with competitive premium cabin options. Austrian Airlines may provide direct or single-stop itineraries optimized for Vienna arrivals and typically includes Austrian hospitality and seamless connections for European onward travel. KLM and Air France route through Amsterdam and Paris respectively, offering frequent schedules and SkyTeam benefits. British Airways connects via London with varied fare classes and useful Oneworld partnerships. Compare total travel time, layover airport convenience, baggage allowances, and loyalty program benefits when choosing an airline. CTA: Use multi-airline search tools to compare fares and schedules from Lufthansa, Austrian Airlines, KLM, and British Airways for your May BOS→VIE trip.