Compare AI tools

	Symphony A	Hugging Face S	Perplexity S	Windsurf A
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.	The GitHub of AI. Models, datasets, spaces — all in one.	AI search done right. Cited answers, not chat theater.	Codeium's agentic IDE. Cascade agent + strong free tier.
Category	Agents	Dev Platform	Research	Coding
Pricing	Free (open-source)	Free + $9-$20/mo + enterprise	Free + $20/mo Pro	Free + $15/mo Pro
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.	Any ML/AI developer. Hobbyists exploring open models.	Replacing Google for any question where you want a cited answer in seconds.	Developers who want Cursor-like power for less money.
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	Largest open-source AI model hub Hosted inference via Spaces + Inference Endpoints Great community	Sources every claim Fast, current answers Pro Search runs multi-step research Spaces for persistent context	Cheaper than Cursor Cascade agent for multi-file tasks Solid free tier
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	Overwhelming for beginners Hosted inference pricing varies	Not a general chatbot Answers can be shallow on complex topics	Smaller community Model selection more limited
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 infrastructure. The one platform every AI dev eventually uses.	S-tier for search. I use it before Google now. If you're still Googling everything, try this for a week.	A-tier. Close second to Cursor. If $5/mo matters, start here.
Link	Open →	Open →	Open →	Open →