About NewStack.ai

An encyclopedia for the AI stack

NewStack.ai explains the modern AI stack in plain English: one short, current, well-linked entry per term, from tokens and transformers to agents, evals, and safety. It is written for developers and for everyone who builds alongside them.

Illustration: A warm editorial workshop at dusk, built as an isometric diorama. At a large drafting desk, a small faceless figure files glowing index cards into a tall cabinet of eight stacked...

Why it exists

The AI ecosystem mints a new acronym every week, and most explanations are either a sales page or a research paper. NewStack.ai sits in between. Every entry opens with a short plain-English definition, then explains how the thing works, where it sits in the stack, and what to read next.

It is a reference, not a news feed: bookmark it, search it, and come back when the next term lands in your standup.

Eight layers, one per section

The logo is a stack of eight colored layers, one for each section of the site. Read top to bottom, they follow the same order as the navigation.

  1. Core Concepts - the vocabulary everything else builds on: LLMs, tokens, embeddings, and fine-tuning.
  2. Models & Providers - the model families that matter and how to choose between them.
  3. Retrieval & Data - RAG, vector databases, chunking, and the pipelines that ground a model in your data.
  4. Agents & Orchestration - agents, tool use, MCP, and the frameworks that turn a model into software that acts.
  5. Inference & Serving - where models actually run: hosted APIs, GPUs, local runtimes, caching, and streaming.
  6. Evals & Observability - how teams know their AI works: evals, LLM judges, tracing, and cost tracking.
  7. AI Coding - coding agents, vibe coding, spec-driven development, and AGENTS.md.
  8. Safety & Governance - prompt injection, jailbreaking, alignment, regulation, and model cards.

How entries are written

  • Definition first. Every entry leads with a short definition you could repeat in a meeting, and every index card carries a one-sentence version.
  • Plain English. Jargon is explained the first time it appears, or linked to its own entry.
  • Linked. Each entry points to three to five related entries, so you can follow an idea across the stack.
  • Kept current. The home page and the fastest-moving sections (models, agents, and coding) are re-checked against current sources twice a month, and the other sections rotate through the same review.
  • Claims labeled. Benchmark scores and prices are stated as vendor claims with a date, not repeated as settled fact.

Who builds it

NewStack.ai is written and maintained by RJ Lindelof and built with RJL.ai.

Looking for opinionated tool picks and hands-on tutorials instead of definitions? That is the job of our sister site, newstack.dev.

Contact

Questions, corrections, or a term we should add? Send a message. Corrections are the most useful thing a reader can send: choose Correction as the topic and name the page.

Replies go to the email address you enter in the form.