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.
Normalization (LayerNorm, RMSNorm, BatchNorm)
Normalization rescales a layer's activations to a stable mean and scale so deep networks train faster. How BatchNorm, LayerNorm and RMSNorm differ.
Graph Neural Networks (GNN)
A GNN takes adjacency as data, not as an architectural assumption. Message passing worked by hand, why k layers reach d^k nodes, and why deep GNNs collapse.
Training
Training fits a model's parameters to data: forward pass, measure the loss, backward pass, nudge every weight downhill, repeat until the loss stops falling.
LLM-as-a-Judge
Using one model to grade another's output against a rubric: how it works, the biases that break it, and the human agreement rate you can actually reach.
Ambient Clinical Documentation
AI scribes draft the clinical note from consultation audio. What the largest deployment and the randomised trials measured — and who stays liable.
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.