PlanetScale

The open-source Firebase alternative

Open-source Firebase alternative providing a full backend-as-a-service on PostgreSQL. Auto-generated REST and GraphQL APIs from your schema, real-time subscriptions, built-in auth with 20+ social providers and Row Level Security, S3-compatible file storage with CDN, and Deno-powered Edge Functions. Visual dashboard with SQL editor and table editor. Supports pgvector for AI apps. Self-hostable or managed with a generous free tier. 75K+ GitHub stars.

Serverless Postgres

Serverless Postgres platform separating storage and compute for branching, autoscaling, read replicas, instant restore, and scale-to-zero workloads. Neon works with standard PostgreSQL clients and ORMs, supports extensions such as pgvector, and sits inside a broader Neon backend platform with Auth, Data API, Functions, Object Storage, and AI Gateway features.

SQLite for production

Edge-hosted distributed database built on libSQL (an open-source fork of SQLite) designed for low-latency data access worldwide. Features multi-region replication, embedded replicas that sync to your application server for microsecond reads, database branching for development workflows, and point-in-time recovery. Ideal for edge computing, serverless functions, and mobile apps. Compatible with SQLite ecosystem tooling. Generous free tier with 9GB storage and 500 databases.

High-recall Postgres vector search at billion scale

VectorChord is a Postgres extension from the supervc-stack/VectorChord project that brings high-recall vector search to PostgreSQL. As the spiritual successor to pgvecto.rs, it combines IVF indexes with RaBitQ quantization to deliver Pinecone-class performance at billion-vector scale while keeping all data inside a single Postgres database — no separate vector store, no two-system sync, no rewrites when the workload grows.

AI-native database for hybrid RAG retrieval

Infinity is an AI-native database from InfiniFlow that unifies dense vectors, sparse vectors, tensors, and full-text search in a single engine. Built for retrieval-augmented generation (RAG) at scale, it powers hybrid search workflows where lexical matching, semantic similarity, and reranking all happen against one storage layer instead of four loosely coupled services.

Vector search extension for SQLite that runs anywhere

sqlite-vec is a lightweight vector search extension for SQLite written in pure C with zero dependencies. It brings nearest-neighbor search capabilities directly into SQLite databases, enabling AI applications to store and query embeddings without running a separate vector database. The extension works everywhere SQLite runs including Linux, macOS, Windows, WebAssembly in browsers, and even Raspberry Pi devices. Sponsored by Mozilla Builders, Fly.io, and Turso.

Enterprise RAG framework by Tencent

WeKnora is a Tencent-developed LLM-powered knowledge management and Q&A framework for enterprise document understanding and semantic retrieval. Supports 10+ document formats including PDF, Word, Excel, and images with seamless IM platform integration for WeCom, Feishu, Slack, and Telegram. Offers Quick Q&A mode using RAG pipelines and Intelligent Reasoning mode with ReACT agents for complex multi-step reasoning tasks across organizational knowledge bases.

Declarative multimodal AI data infrastructure

Pixeltable is a declarative data infrastructure for multimodal AI that stores video, audio, images, and documents as first-class column types. Define Python computed columns for inference and transformations, and Pixeltable auto-orchestrates execution with incremental updates. Built-in vector search eliminates the need for separate vector databases while supporting RAG and semantic search workflows.

Fast embeddable vector search engine

USearch is a high-performance vector search engine implementing HNSW algorithms for approximate nearest neighbor queries across C++, Python, JavaScript, Rust, Java, Go, and more. It supports user-defined distance metrics, memory-mapped persistence for datasets larger than RAM, and filtered search with predicates. Used by YugabyteDB and ScyllaDB as their production vector indexing backend.