Companies that are doing programmatic buying on native ad inventory include major ad networks like Taboola, Outbrain, and TripleLift. These platforms specialize in programmatically buying native ad space across a variety of websites and publishers. Other companies like Revcontent and Bidtellect also focus on programmatic native ad buying. Additionally, large digital advertising players such as Google and Facebook allow programmatic buying for native ads through their platforms. These companies use algorithms and AI to optimize ad placement, targeting, and bidding, ensuring advertisers can reach their desired audience effectively.