...Perplexity has become a surprisingly strong player in a market otherwise dominated by OpenAI, Microsoft, Google and Meta.

At its core, Perplexity is a search engine.

...over the past year, Perplexity has evolved rapidly. It now has its own search index and has built its own LLMs based on open source models. They’ve also begun to combine their proprietary technology products. At the end of November, Perplexity announced two new “online LLMs” — LLMs combined with a search index — called pplx-7b-online and pplx-70b-online. They were built on top of the open source models mistral-7b and llama2-70b.

Using open source models has been critical for the growth of Perplexity.

...the default Perplexity model still relies on GPT 3.5 (and a dash of LLaMA-2). But the intention is to move away from that long-standing reliance on OpenAI for its base model.