Look up any term in AI.
Definitions that explain the actual mechanism — not a paraphrase of the name. Written for people who have to build with this, or decide about it.
Glossary
256 terms, each with a worked definition, how it actually works, and where it breaks.
Browse A–ZModels
What each model is good at, what it costs per token, and when the size matters.
Compare modelsAI tools
68 tools across 11 categories, with pricing and status kept current.
Browse the directoryExplainers
Longer pieces on the things a definition cannot hold: benchmarks, costs, and claims worth checking.
Read the blogStart with the load-bearing ideas
The terms the rest keep referring back to. Read these and most AI writing stops being opaque.
Agent2Agent Protocol (A2A)
An open standard, governed by the Linux Foundation, that lets independent AI agents discover each other and delegate tasks across vendors and frameworks.
AI for Good
AI for Good is an aspiration, not a technique, and nothing certifies the label. Here it is tested against named projects with published, measured results.
Causal Reasoning
Why a model trained on observational data cannot tell cause from correlation, what that costs when you act on it, and what actually identifies one.
Supervised Fine-Tuning (SFT)
Supervised fine-tuning trains a pretrained language model on curated prompt-response pairs with next-token loss, teaching it to follow instructions.
Text Analysis
Turning unstructured text into structured data — the concrete NLP task catalog: classification, sentiment analysis, entity extraction and topic modeling.
Model Deployment
What has to happen between a model that trains well and users calling it: replica sizing, latency budgets, cold starts, and the rollback nobody built.
Recently updated tools
Every listing carries a status. When a product is renamed, sunset or acquired, the page says so.
AgentGPT
Reworkd AI · Web Application
Open-source, browser-based autonomous AI agent from Reworkd. You name a goal, the agent plans tasks, executes them, and learns from the results.
FreemiumDola (formerly Cici)
ByteDance · Web, Mobile & Desktop Application
ByteDance's overseas AI assistant, renamed from Cici in November 2025. Free chat, translation and image generation, region-locked out of the US and China.
FreeKimi Code
Moonshot AI · CLI Tool & Editor Integration
Moonshot AI's open-source terminal coding agent: an MIT-licensed CLI with MCP and editor integration, driving Kimi K3 and K2.7 Code via Kimi membership.
FreemiumBuilt something worth listing?
Send it in. Listings are free, we test before we publish, and we write the description ourselves.