You asked about B2B
Nobody in the register described anything this way.
| Launched | What it was | Today |
|---|---|---|
| 2023-01-01 | YCStackAI The Enterprise AI Transformation Platform · stackai.com | acquired |
| 2023-01-01 | YCPlayAI Our mission is to make Voice AI accessible and useful to all. · play.ai | acquired |
| 2023-01-01 | YCFern Instantly offer SDKs and API Docs · buildwithfern.com | acquired |
| 2023-01-01 | YCLangfuse Open source LLM engineering platform · langfuse.com | acquired |
| 2023-01-01 | YCVersori Agentic integrations & automations for enterprise · versori.com | acquired |
| 2023-01-01 | Know what your LLM is doing — and why it’s failing · traceloop.com | acquired |
| 2023-06-01 | Metadata for GenAI workflows · deasylabs.com | acquired |
| 2023-01-01 | The open source, fullstack monitoring platform: stop guessing why… · highlight.io | acquired |
| 2023-06-01 | YCMocha Build and publish web apps in minutes. No coding required. · getmocha.com | acquired |
| 2023-01-01 | Usage Metering, AI & API Monetization · openmeter.io | acquired |
| 2023-01-01 | YCFintool Financial copilot for institutional investors · fintool.com | acquired |
| 2023-01-01 | Automate outbound with signals · bluebirds.ai | acquired |
| 2023-01-01 | YCKeep The open-source AIOps platform · keephq.dev | acquired |
| 2023-06-01 | Open source GenAI development platform · flowiseai.com | acquired |
| 2023-01-01 | YCOfOne AI-powered order taker for restaurant drive-thrus · of.one | acquired |
| 2023-01-01 | YCEdgeBit Autofix your software dependencies · edgebit.io | acquired |
| 2023-01-01 | YCMulligan AI automation for insurance brokerages · insurestack.ai | acquired |
| 2023-01-01 | YCLume Speed up customer implementation with AI · lume.ai | acquired |
| 2023-01-01 | YCHelicone LLM Observability for Developers · helicone.ai | acquired |
| 2023-01-01 | YCTrigo Rent verification API for landlords and lenders · trigodata.com | acquired |
| 2023-01-01 | The interface for your database · outerbase.com | acquired |
| 2023-01-01 | YCBrewit Conversational data analytics for every team · brewit.ai | acquired |
| 2023-06-01 | YCPincites Close deals faster with AI for contract negotiation · pincites.com | acquired |
| 2023-06-01 | Web, Desktop, and Mobile apps with one codebase in Rust · dioxuslabs.com | acquired |
| 2023-06-01 | YCGlide Crypto Deposits, Wallet Funding, and Pay-with-crypto Infra · buildwithglide.com | acquired |
| 2023-01-01 | YCOpenInt Open Source Embedded Product Integrations · openint.dev | acquired |
| 2023-06-01 | YCXeol Close your outdated dependency attack vector · xeol.io | acquired |
| 2023-06-01 | YCWatto AI AI-powered McKinsey-quality reports in seconds · watto.ai | acquired |
| 2023-01-01 | YCVocode Open source Voice AI · vocode.dev | acquired |
| 2023-01-01 | AI Co-Pilot for Health Insurers to Authorize Treatment Faster · fairwayhealth.co | acquired |
| 2023-01-01 | YCBooth AI Generative AI Photographer for E-Commerce · booth.ai | acquired |
| 2023-01-01 | Delinquency reduction and automation software for institutional… · getcobblestone.com | acquired |
| 2023-01-01 | YCCardinal Your AI product backlog · cardinalapp.io | acquired |
| 2023-06-01 | YCTremor The UI toolkit for Dashboards · tremor.so | acquired |
| 2023-06-01 | YCAutotab AI agents reliable enough to do real work · autotab.com | acquired |
| 2023-06-01 | YCOpenPipe Turn expensive prompts into cheap fine-tuned models · openpipe.ai | acquired |
| 2023-06-01 | YCInari Your junior AI product manager · useinari.com | acquired |
| 2023-01-01 | Modern analytics for CPG brands · muffindata.com | acquired |
| 2023-01-01 | YCDashdive Break down AI and cloud costs by feature and customer · dashdive.com | acquired |
| 2023-01-01 | YCArroyo Cloud-native stream processing · arroyo.dev | acquired |
| 2023-01-01 | YCViddy A new way to create landing pages that is video-native. · viddyapp.io | acquired |
| 2023-01-01 | Open source tools & services for reliable AI Agents & AI Applications · dagworks.io | acquired |
| 2023-01-01 | Sales Agents with 100+ data sources to close more deals · persana.ai | acquired |
| 2023-06-01 | YCChatter Dead simple LLM testing and iteration · chatter.anish.xyz | acquired |
| 2023-06-01 | YCFragment Turn manual operations into scalable processes · checkfragment.com | acquired |
| 2023-06-01 | YCPeerDB Fast, native ETL for Postgres 🐘 🚀 · peerdb.io | acquired |
| 2023-06-01 | YCContinue Pioneering open-source coding agent · continue.dev | acquired |
How this compares
The register re-probes every domain it holds. Some that answered last month stop answering. We send that list — what went quiet, and what it was — once a month. Nothing else.
How this was made. Show HN entries are every post from 2021 to 2023 with at least five points that linked to its own domain; code hosts and free hosting are excluded, because a repository outlives the effort behind it. Product Hunt entries needed 100 votes — a far higher bar, so they are the promoted top slice rather than a like-for-like sample. Both are judged by asking the domain whether it still answers: gone means it no longer resolves, refuses the connection, serves a parking page, or says plainly that it shut down. An HTTP error is not counted as gone — a server answering 404 is one somebody still pays for, and an audit of 25 gone-calls found two such sites alive with only a moved homepage. Y Combinator entries use the status YC publishes itself, which is why only those can say acquired. Squatted domains — a lapsed name now serving somebody else's site — are not detected, so these figures run slightly low.