libSQL bridges the gap between SQLite's legendary simplicity and the server-accessible database model developers expect from PostgreSQL and MySQL, adding network access, replication, and vector search while maintaining full file format and API compatibility. The sqld (SQL daemon) component transforms SQLite into a network-accessible database server accepting queries via HTTP with JSON payloads, WebSocket connections, and a Hrana protocol optimized for low-latency edge access. Client libraries for TypeScript, JavaScript, Rust, Go, and Python connect to sqld identically to any traditional client-server database, while the LD_PRELOAD compatibility layer enables switching existing SQLite applications from local to remote mode without code changes. Embedded replicas synchronize a local SQLite copy inside your application process with the primary server, delivering sub-millisecond read latency while maintaining consistency through streaming replication. Bottomless replication continuously backs up database state to S3-compatible object storage with generation-based snapshots and WAL page shipping, providing point-in-time recovery without manual backup scheduling. Native vector search enables semantic similarity queries directly within SQL using cosine distance functions, eliminating the need for external vector database infrastructure. Read replica support distributes query load across multiple sqld instances, and integration with mvSQLite adds multi-version concurrency for high-availability deployments. Created by Turso with 17,100+ stars and active production deployment. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Live web search plus an LLM of your choice: Farfalle is an open-source, self-hosted answer engine in the Perplexity mold. Queries route through one of several search providers - self-hosted SearXNG for a fully independent stack, or Tavily, Serper, and Bing APIs - and the model composes a cited answer from the retrieved results. Model flexibility is the core design: run llama3, mistral, gemma, or phi3 locally through Ollama for zero per-query cost and full privacy, use cloud models like GPT-4o or Groq-hosted Llama 3 for speed, or route to any provider via LiteLLM. An Expert Search mode uses an agent that plans a multi-step search strategy and executes it for harder questions, and chat history keeps prior research sessions available. The stack is a Next.js and shadcn/ui frontend over a FastAPI backend with Redis rate limiting, shipped as a pre-built Docker image. A browser search-engine entry pointing at your instance makes it the default search from the address bar. Paired with SearXNG and Ollama, the whole pipeline runs with no external API at all.

Achieving 98.4% Recall@5 on LongMemEval-S without a reranker, AKB is the agent-native knowledge infrastructure giving Claude Code, Cursor, Windsurf, and any MCP-aware agent persistent organizational memory — a drop-in replacement for Confluence or Notion where AI agents read and write directly rather than scraping human-formatted pages. Documents are stored as Markdown with YAML frontmatter in Git bare repositories (full version history, branching, diff), while PostgreSQL 16 serves as source of truth for chunk text, metadata, and BM25 vocabulary, with dense embeddings handled by a pluggable vector store (pgvector default, Qdrant optional, or managed Seahorse). Agents interact through 20+ MCP tools — akb_put, akb_search, akb_browse, akb_relations, akb_sql, akb_edit, akb_history — performing hybrid dense plus BM25 search fused via Reciprocal Rank Fusion in one call. The URI graph (depends_on, related_to, implements relations) lets agents traverse knowledge connections without external graph databases. Multi-tenant vault isolation is enforced at the PostgreSQL ACL level with per-user roles and SET LOCAL ROLE for SQL sandboxing. Event fanout streams structured events to Redis Streams for external consumers (synthesis bots, digest agents, audit trails), and a hash-chained append-only audit log integrates with enterprise SIEMs. Ships with agent plugins for Claude Code and Codex (session capture, wiki ingest, lifecycle hooks), Kubernetes kustomize manifests, and Open Knowledge Format export. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. BSL 1.1 licensed (free under 100 seats, auto-converts to Apache 2.0 after four years).

Point Sourcebot at your GitHub, GitLab, Bitbucket, Azure DevOps, Gerrit, or Gitea repositories and get regex, symbol, and filtered search results in under a second across thousands of repos and branches. Backed by Y Combinator with production deployments at NVIDIA, Shutterstock, SeatGeek, Arista, and Red Hat, the Zoekt-powered engine deploys as a single Docker container with zero external data transmission. Ask Sourcebot connects reasoning models like Claude Opus to your entire codebase, enabling natural language questions that return structured answers grounded with inline citations and navigable code snippets, backed by automatic tool calls that search code, follow references, and read files across all indexed repositories. Ask connectors extend this to Jira, Slack, Linear, and Confluence via MCP, pulling external context alongside code for debugging and documentation. IDE-level code navigation provides goto definition and find all references across repository boundaries without local cloning. The built-in file explorer renders any indexed file with syntax highlighting, breadcrumb navigation, and git blame showing per-line commit attribution. An analytics dashboard tracks daily, weekly, and monthly search activity. Permission syncing from GitHub and GitLab enforces access control lists so users only see repositories they are authorized to access. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Other licensed.

Kotaemon is a document QA platform that combines advanced RAG techniques with a clean Gradio-based web interface for chatting with your documents. Built by Cinnamon, the Python backend supports any LLM provider including OpenAI, Azure OpenAI, Cohere, Groq, and local models via Ollama and llama-cpp-python, with a model management panel for configuring LLM and embedding providers from the UI. The default hybrid RAG pipeline combines full-text keyword retrieval with vector similarity search and applies re-ranking to ensure optimal result quality, while multi-modal document parsing extracts content from tables and figures alongside text. Advanced citations link every answer to specific source passages with relevance scores, viewable directly in the built-in PDF viewer with highlighted text spans. GraphRAG indexing via NanoGraphRAG, LightRAG, or Microsoft GraphRAG builds knowledge graphs from document collections for relationship-aware retrieval. Agent-based reasoning supports question decomposition for multi-hop queries using ReAct and ReWOO strategies. Multi-user authentication organizes documents into private and public collections with sharing and collaboration features. The platform supports Docker deployment in lite, full, and Ollama-bundled variants, runs on port 7860, and stores application data in a persistent volume. MCP tool integration enables external system connections for extended retrieval capabilities. On RepoCloud, deploy Kotaemon on a dedicated VPS with Docker, root SSH access, and complete control over your document AI infrastructure, all under the Apache 2.0 license.

With over 70,000 GitHub stars and billions of documents indexed across enterprises like Uber, Netflix, and Wikipedia, Elasticsearch is the world's most deployed search engine, powering everything from application search to security analytics and AI-driven retrieval. Built on Apache Lucene, its inverted index architecture delivers sub-second full-text search across terabytes of data with BM25 relevance scoring, configurable analyzers for 30+ languages, and fuzzy matching for typo tolerance. The kNN vector search API uses the HNSW algorithm for approximate nearest neighbor queries on dense and sparse embeddings up to 4,096 dimensions, while reciprocal rank fusion enables hybrid search that combines lexical and semantic signals in a single query. Elasticsearch's aggregation framework supports metric, bucket, and pipeline aggregations for real-time analytics directly on indexed data without separate OLAP infrastructure. The cluster distributes data across shards with automatic rebalancing, replica allocation, and cross-cluster search for multi-datacenter deployments. Kibana provides the visualization layer with dashboards, Lens visual editor, Canvas for pixel-perfect reports, and Discover for ad-hoc log exploration. Ingest pipelines with processors like grok, dissect, GeoIP enrichment, and inference handle data transformation at index time, and ES|QL brings pipe-based query syntax with joins and columnar processing. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL v3 licensed.

Perplexity's answer-engine experience, self-hostable and open-source: Morphic searches the web and writes cited answers. Instead of returning a list of links, it searches the web, reads the sources, and generates a complete answer with inline numbered citations. The generative UI streams rich components, source cards with thumbnails, image grids, syntax-highlighted code, and LaTeX math, rather than plain markdown. Quick mode answers fast; Adaptive mode runs deeper multi-step research. Search backends are pluggable: the Docker Compose bundle ships with a private SearXNG instance so no search API key is required, and Tavily, Brave, and Exa are supported alternatives. LLM providers include OpenAI, Anthropic, Google, Ollama, and any OpenAI-compatible endpoint, with per-mode model mapping - fast, cheap models for quick searches, stronger models for adaptive research, tuning the cost-quality trade-off per query type. An inspector panel exposes tool execution during multi-step research, and AI-suggested follow-up questions keep an investigation moving. Chat history persists in PostgreSQL, results are shareable by URL, file uploads feed context into queries, and optional Supabase authentication adds multi-user or guest access. Because the default search path is your private SearXNG instance, research topics never hit a commercial search API - and with local Ollama models the marginal cost of a query approaches zero. Built with Next.js, TypeScript, and the Vercel AI SDK under Apache 2.0.

RAGFlow has established itself as one of the most widely adopted open-source RAG engines available, powering production AI systems that demand traceable, hallucination-free answers from complex enterprise data. The platform processes PDF, DOCX, Excel, and PPT files through vision-based deep document understanding with layout analysis and OCR, extracting structured knowledge from tables, charts, and images that simpler parsers miss entirely. RAGFlow's hybrid retrieval pipeline combines vector search with BM25 keyword matching and multi-stage reranking across configurable document stores including Elasticsearch, InfiniFlow's Infinity engine, OpenSearch, and OceanBase. Developers connect any combination of LLM providers — OpenAI, DeepSeek, Anthropic Claude, Google Gemini, and locally-hosted models via Ollama — through a unified configuration layer. The visual agent workflow system enables multi-step reasoning chains with persistent memory, tool calling, and pre-built templates for common enterprise scenarios. RAGFlow synchronizes data from Confluence, S3, Notion, and Google Drive, and delivers answers through chat integrations with Feishu, Discord, Telegram, and Line. The Python SDK and RESTful API on port 9380 provide programmatic access to knowledge base management, document parsing, and conversational retrieval. The full stack deploys via Docker Compose with MySQL for metadata, Redis for task orchestration, and MinIO for object storage. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.

Google's search results without Google's surveillance: Whoogle is a self-hosted proxy that strips the tracking and keeps the results. Your query goes from browser to your Whoogle instance, which fetches results from Google with a randomly generated User Agent and strips everything hostile before returning them: no ads or sponsored content, no third-party JavaScript or cookies, no AMP links, no URL tracking tags like utm_source, no referrer header - and Google sees your server's IP, never yours. Unlike metasearch engines that blend sources, Whoogle proxies Google exclusively, so result quality is exactly what you'd get logged out and incognito, minus the noise. A lightweight Flask app configured entirely through environment variables, it supports DuckDuckGo-style bang shortcuts, autocomplete suggestions, safe search, per-country and per-language filtering, site blocklists, and automatic rewriting of social links to privacy front-ends like Nitter and Invidious. Privacy hardening goes further: built-in Tor routing makes Google see an exit node instead of your server, HTTP/SOCKS proxy support covers other setups, and POST-based queries keep search terms out of logs. Light, dark, and fully custom CSS themes plus browser search-engine registration make it a drop-in default on desktop and mobile. Stateless, tiny, and trivial to run.

JobSpy API turns seven major job boards into a single REST endpoint, aggregating listings from LinkedIn, Indeed, Glassdoor, Google Jobs, ZipRecruiter, Bayt, and Naukri through one GET request. Built on FastAPI with the Python JobSpy scraping library, the API returns structured JSON or downloadable CSV containing job titles, companies, locations, salaries, descriptions, posting dates, and direct application URLs. Filters cover search terms, location, distance radius, job type (full-time, part-time, contract, internship), remote status, hours since posting, country, and salary range. Interactive Swagger UI and ReDoc interfaces provide try-it-now functionality for testing queries directly in the browser. Security includes x-api-key header authentication with configurable rotation, per-endpoint rate limiting with adjustable thresholds, and response caching with configurable TTL to reduce redundant scraping. Global proxy support routes outbound requests through HTTP/HTTPS proxies to avoid IP-based rate limiting from job boards. Environment variables control everything from default search parameters and logging levels to CORS origins and documentation paths. Health check and ping endpoints integrate with uptime monitoring services. Docker Compose exposes the API on a configurable port. MIT licensed.

One clean interface in front of Anthropic, OpenAI, Google Gemini, Cohere, and more: Chat Chat is a Next.js front door to the major AI providers, ending the juggling of separate subscriptions, tabs, and UIs per model. Bring your own API keys, pick a provider and model per conversation, and switch between them as the task demands: Claude for long-form reasoning, GPT for code, Gemini for multimodal work - the interface stays identical. Beyond configured presets, custom providers plug in with their own API endpoints and keys, which covers OpenAI-compatible gateways and local inference servers. The design splits into two dedicated modes: a chat interface for conversational work with customizable system prompts, and a search interface that pairs AI processing with query handling for research-style questions. The stack is modern and hackable - Next.js 14, Tailwind CSS, shadcn/ui on Radix primitives, Jotai for state - with full internationalization including English, Chinese, and Japanese. Self-hosting means your conversation history and API keys live on your instance rather than a third-party wrapper service, and pay-per-token API pricing typically beats stacking multiple monthly chat subscriptions. AGPL-licensed and deliberately simple to deploy: one container, environment variables for keys, done.