Compare AI tools

	Symphony A	NotebookLM S	Lex A	GitHub Copilot B
Tagline	OpenAI's open-source daemon that turns your Linear board into an always-on coding agent factory — tickets go in, pull requests come out.	Google's research notebook. Turns your docs into a podcast.	Google Docs with an AI collaborator baked in.	Microsoft/GitHub's autocomplete. Deep VS Code + JetBrains integration.
Category	Agents	Research	Writing	Coding
Pricing	Free (open-source)	Free	Free + $12/mo	Free (limited) + $10/mo Pro + $19/mo Business
Best for	Engineering teams already using Linear + OpenAI Codex who want to stop babysitting agent sessions and instead let the issue tracker drive autonomous coding at scale.	Students, researchers, anyone with a stack of PDFs or a topic to learn.	Essays, long-form drafts, thinking on the page.	Teams with GitHub already. Devs who don't want to change IDEs.
Strengths	Fully autonomous ticket-to-PR pipeline: every open Linear issue gets its own isolated Codex agent without manual supervision Fault-tolerant Elixir/OTP architecture automatically restarts crashed agents and manages hundreds of concurrent runs WORKFLOW.md keeps all orchestration policy version-controlled inside the repo, so agent behavior is reproducible and reviewable like code Proven internal results: OpenAI reported a 500% increase in landed PRs on some teams within three weeks Open spec encourages community re-implementations in any language, not just Elixir	Upload anything, ask questions, get cited answers Audio Overview turns docs into a 10-min podcast Great for studying	Clean writing UX — distraction-free +++ prompt triggers AI help Collaboration + AI feedback together	Great enterprise story Works in your existing IDE Chat + autocomplete
Weaknesses	Currently only supports Linear as an issue tracker — GitHub Issues and Jira integrations are not yet official Only OpenAI Codex is officially supported as the agent runtime; other model integrations are community-contributed and incomplete Self-hosted, Elixir-dependent engineering preview with no built-in sandboxing — not suitable for untrusted or production environments out of the box	Google-only Can be slow on large corpora	Less feature-rich than Google Docs AI ceiling below dedicated tools	Less agentic than Cursor/Claude Code Model quality varies
Kai's verdict	Symphony is the most architecturally serious 'issue tracker as control plane' approach yet — 15K GitHub stars in weeks confirms the idea resonates — but it's still a rough, self-hosted engineering preview that demands Elixir chops and a Linear-only workflow. (Verdict pending Phi's full review.)	S-tier for study. The Audio Overview is a killer feature. Try it with three of your favorite PDFs.	A-tier. Beautiful UX. The writing app I'd pick if I only wrote long-form.	B-tier. Solid for autocomplete but the category moved past it. Pick Cursor unless you can't.
Link	Open →	Open →	Open →	Open →