Perplexity is an answer engine that reads the web for you and writes a sourced summary, with footnote-style citations under every claim. Free tier covers everyday lookups; Pro ($20/mo) unlocks unlimited Pro Search, Deep Research, and the Comet browser agent. The Sonar and Search APIs let developers wire the same real-time web Q&A into their own products.

Hex is an AI analytics platform with collaborative notebooks combining SQL, Python, no-code charts, and AI-powered analysis. Used by Ramp, Figma, Anthropic, and thousands of data teams for ad-hoc exploration, dashboards, and self-serve apps.

ChatPDF is an AI assistant for reading and querying PDFs, Word docs, PowerPoint files, YouTube videos, and websites, with answers anchored to clickable source citations. Built for students, researchers, and professionals working through long documents.

Sana is an enterprise AI company (now part of Workday) building two products: Sana Learn, an LMS/LXP that converts uploaded documents into interactive courses with an AI tutor, and Sana Agents, an enterprise search and AI agent layer across company apps. Aimed at L&D and operations teams at large organizations.

Glean is an enterprise Work AI platform that unifies workplace search, an AI assistant, AI agents, and a connector library across Slack, Teams, Zoom, ServiceNow, GitHub, Salesforce, and more. Built for enterprises deploying secure AI across engineering, sales, marketing, support, and operations.

Scite is an AI research platform that uses Smart Citations to classify every reference as supporting, contrasting, or mentioning a claim, with the surrounding sentence shown in context. Aimed at academic researchers, students, and analysts working across scholarly articles, patents, clinical trials, grants, and preprints.

ChatGPT is OpenAI's general-purpose conversational AI assistant for writing, research, coding, data analysis, and image generation. Available on web, mobile, and desktop across Free, Go, Plus, Pro, Business, and Enterprise tiers.