Meta CEO Mark Zuckerberg announced that the company's 'open' AI model family, Llama, has reached 1 billion downloads.Llama is Meta's AI assistant, used across platforms like Facebook, Instagram, and WhatsApp.Despite facing setbacks, Llama has been widely successful, with companies like Spotify, AT&T, and DoorDash using its models in production.Meta has plans to launch more Llama models, including 'reasoning' and multimodal capabilities.