The AI tools stack

Character Technologies

Chat platform where users create and converse with custom AI characters — historical figures, fictional personas, or invented experts.

OpenAI

The most widely-used AI chat assistant with image, voice, and a broad ecosystem of plugins and custom GPTs.

ChatPRD

AI assistant for product managers — turns rough ideas into structured PRDs, generates user stories, and critiques specs against PM best practices.

Anthropic

A general-purpose chat assistant known for nuanced reasoning, careful writing, and very long context handling.

Cohere

Enterprise chat assistant grounded in your own documents, with strong RAG, citations, and workplace privacy controls.

DeepSeek

Chinese open-weight model with strong reasoning and coding capabilities at very low cost.

Doximity

Free HIPAA-compliant AI for verified U.S. physicians — drafts clinical notes, prior auth letters, and patient communications inside Doximity's workflow.

Duolingo

Premium tier of Duolingo with AI-powered Roleplay (conversation practice) and Explain My Answer (grammar explanations from a virtual tutor).

Google

Google's multimodal assistant with native integration into Gmail, Docs, Sheets, and the rest of Workspace.

xAI

xAI's assistant with real-time access to X (Twitter) data, useful for tracking live discourse.

Harvey

Domain-trained AI built specifically for elite law firms — handles contract review, legal research, drafting, and transactional analysis with citations.

Hippocratic AI

Healthcare-specific LLM platform for patient-facing use cases — chronic care check-ins, post-discharge follow-ups, and triage — with HIPAA-grade safety.

Hugging Face

Free, open-source chat interface that lets you switch between top open-weight models (Llama, Mistral, Qwen, etc.) — no account required for casual use.

Khan Academy

Khan Academy's AI tutor that uses Socratic dialog to guide students through problems instead of handing them answers — covers math, science, humanities, and SAT prep.

Moonshot AI

Chinese chat assistant with extremely long context windows (up to 2M tokens) and a strong agent mode for browsing and tool use.

Mistral

European chat assistant from Mistral with strong multilingual support and a focus on data sovereignty.

Liner

AI answer engine specifically tuned for academic and trustworthy sources, with inline citations and a "Scholar" mode for paper-grounded research.

Meta

Meta's consumer assistant powered by the open-weight Llama family, available standalone and integrated across WhatsApp, Instagram, Messenger, and Facebook.

Microsoft

Microsoft's chat assistant available across Windows, Edge, and Microsoft 365 — combines GPT models with deep integration into Word, Excel, Outlook, and Teams.

Perplexity AI

A search-grounded answer engine that cites sources for every claim, useful when you need verifiable information.

Inflection AI

Conversational AI tuned for warmth and reflection rather than raw output — designed to help you think through decisions, journal, or just talk something out.

Quora

Single interface to chat with most leading models (Claude, GPT, Gemini, Llama, etc.) plus thousands of community-built bots — pay one subscription, switch freely.

Alibaba

Alibaba's open-weight Qwen models in chat form — multilingual, strong at coding and math, with both reasoning and standard modes.

Speakeasy Labs

Voice-first AI language tutor — real-time spoken conversation with an AI that corrects pronunciation, suggests vocabulary, and adapts to your level.