BlenderBot

BlenderBot (originally 'Blender'), released by Facebook AI Research in April 2020 (arXiv:2004.13637), was at launch the largest open-source chatbot ever created at 9.4 billion parameters — nearly 4x Google's Meena. Its key idea was not just scale but a recipe: fine-tuning on Blended Skill Talk, a dataset fusing three conversational skills — empathy (Empathetic Dialogues), knowledge (Wizard of Wikipedia), and persona (ConvAI2) — so one model could be personable, informed, and empathetic in natural 14-turn flows.

Human evaluators rated it more engaging than contemporary systems including Meena. FAIR open-sourced the 90M, 2.7B, and 9.4B variants along with the datasets and ParlAI training code, making it a cornerstone of reproducible dialogue research. Honest caveats from the original release still apply: no long-term memory, occasional repetition, and factuality gaps — problems the field is still working through.