Half the architecture sketches on the internet trace back to Excalidraw - the MIT-licensed virtual whiteboard whose hand-drawn aesthetic made technical diagramming feel approachable, at roughly 85,000 GitHub stars. The infinite canvas offers rectangles, ellipses, diamonds, arrows with smart binding and labels, free-draw, text, images, and an eraser, with full undo/redo, zoom, dark mode, and keyboard-first ergonomics. Community shape libraries add thousands of pre-built elements - AWS architecture icons, flowchart stencils, UI wireframe kits - and everything exports to PNG, SVG, the clipboard, or the open .excalidraw JSON format that keeps drawings diffable and portable. Live collaboration works on a share-a-link model with live cursors and a laser pointer for presenting, and it is end-to-end encrypted by design: the room key travels in the URL hash, which never reaches the server, so the WebSocket relay only ever sees ciphertext. The architecture is remarkably light - the app is a static bundle served by Nginx, drawings persist locally in the browser, and the stateless excalidraw-room relay handles multiplayer - so a self-hosted deployment gives unlimited boards and collaborators with near-zero resource cost, replacing per-editor whiteboard subscriptions.

With over 107,000 GitHub stars and adoption by teams at Mozilla, 1Password, Peerlist, and thousands of startups, Supabase has become the most widely deployed open-source Firebase alternative — built entirely on PostgreSQL rather than a proprietary NoSQL store. Every project provisions a dedicated Postgres database with 40+ preinstalled extensions, auto-generating REST APIs via PostgREST, GraphQL via pg_graphql, and real-time change streams via an Elixir-based WebSocket engine that supports database change listeners, user presence tracking, and arbitrary broadcast messaging. Authentication covers email and password, phone OTP, magic links, and 20+ social providers including Google, GitHub, Apple, Azure, and SAML SSO, all enforced through Postgres Row Level Security policies that run inside the database itself. S3-compatible object storage delivers files through a CDN spanning 285+ cities with on-the-fly image transformations powered by imgproxy. Edge Functions run globally distributed TypeScript on the Deno runtime with Node.js compatibility and access to over two million NPM packages. The pgvector extension stores, indexes, and queries vector embeddings for AI-powered semantic search and retrieval-augmented generation workflows. Supabase Studio provides a browser-based dashboard with a table editor, SQL editor, schema visualizer, and log explorer. Official client SDKs ship for JavaScript, Python, Flutter, Swift, Kotlin, C#, Go, and Ruby. The self-hosted Docker Compose stack runs fourteen coordinated services including Kong API gateway, Supavisor connection pooler, and Logflare analytics. 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.

Used by over 80% of Fortune 100 companies including LinkedIn, Netflix, Uber, and Goldman Sachs, Apache Kafka processes trillions of messages per day as the world's most widely deployed distributed event streaming platform. Since version 4.0 released in March 2025, Kafka operates exclusively with KRaft consensus, replacing Apache ZooKeeper entirely with an internal Raft-based metadata quorum managed by controller nodes, reducing operational complexity and eliminating external coordination dependencies. Topics are organized as append-only partitioned commit logs with configurable replication factors across brokers, delivering network-limited throughput with end-to-end latencies as low as 2 milliseconds. Kafka Streams provides a client library for building stateful stream processing applications with exactly-once semantics, windowed aggregations, joins across streams and tables, and interactive queries against local state stores. Kafka Connect integrates with hundreds of systems including PostgreSQL, MySQL, Elasticsearch, Amazon S3, MongoDB, HDFS, and JMS through a standardized connector framework with distributed worker mode and automatic offset management. Share Groups introduced in version 4.2 deliver queue-style consumption semantics alongside traditional consumer groups, enabling Kafka to serve both pub-sub and point-to-point messaging patterns natively. The Schema Registry enforces Avro, Protobuf, and JSON Schema compatibility rules across producers and consumers, preventing schema evolution from breaking downstream applications. Tiered Storage offloads older log segments to object storage like S3 while maintaining transparent consumer access, dramatically reducing local broker storage costs for long-retention topics. 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.

Scheduling infrastructure, not just a booking page - Cal.com is the leading open-source scheduling platform. Share a link, attendees pick a slot, and real-time sync against Google Calendar, Outlook, and CalDAV prevents double-booking. Beyond the basics it covers team workflows: round-robin distribution, collective availability across multiple hosts, recurring meetings, and routing forms that ask bookers questions and send them to the right team member - the feature sales and support teams usually pay enterprise prices for. Paid bookings run through Stripe, video calls through the built-in Cal Video (Daily.co) or Zoom and Google Meet, and an app store connects 100+ tools including HubSpot, Zapier, and n8n. The API-first architecture with webhooks and embeds makes it practical to build scheduling into your own product, white-labeled with your domain and branding. Built on Next.js and Prisma over PostgreSQL, translated into 65+ languages, with the self-hostable community codebase maintained under an open-source license.

With over 47,000 GitHub stars, Cal.diy is the fully open-source community fork of Cal.com that strips away every proprietary license gate and enterprise paywall to deliver a pure MIT-licensed scheduling platform you completely own. The booking engine supports individual event types including recurring events, seated events with capacity limits, and paid bookings through Stripe and PayPal, all backed by customizable availability schedules with date overrides, buffer times, minimum notice periods, and travel schedule support. Calendar synchronization is bidirectional across nine providers — Google Calendar, Outlook and Office 365, Apple Calendar, CalDAV, Lark, Feishu, Zoho, Exchange, and ICS feeds — so every booking automatically appears on your existing calendar while blocking conflicting slots. Video conferencing links generate automatically for Zoom, Google Meet, Microsoft Teams, Webex, Jitsi, Daily.co, Whereby, and Huddle01, eliminating manual link management. The automation layer connects through webhooks, Zapier, n8n, Make, and Pipedream to CRM platforms like HubSpot, Salesforce, and Close, messaging services including Discord, Telegram, and WhatsApp, and analytics tools such as Google Analytics 4, PostHog, and Fathom. The entire application is built on the T3 stack — Next.js for server-rendered pages, tRPC for end-to-end type-safe APIs, Prisma for PostgreSQL database access, and Tailwind CSS for the responsive interface. Unlike Cal.com's open-core model, Cal.diy requires no license key and includes no gated features. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Real-time collaborative Markdown behind your own firewall: HedgeDoc (formerly CodiMD, descended from HackMD's open-source edition) keeps team notes on team infrastructure. Share a note's URL and collaborators are editing together instantly - live cursors, changes appearing keystroke by keystroke - in a three-mode interface that toggles between raw Markdown, rendered preview, and side-by-side split. The Markdown dialect is extended where engineers need it: Mermaid, Graphviz, and Vega-Lite diagrams, MathJax for equations, syntax-highlighted code blocks, embedded content, and a presentation mode that turns a note into reveal.js slides with a single YAML header. A dropdown permission system controls each note - freely editable, limited to signed-in users, or locked read-only - and published notes become clean read-only pages for wider distribution. Revisions track every change with the ability to revert to any earlier version. The AGPL-3.0 codebase is light enough to run on a Raspberry Pi and deploys via Docker with PostgreSQL, MySQL, or SQLite. Authentication covers LDAP, SAML, OAuth2, and email. It deliberately stays a focused document editor - no page trees or kanban - and does that one job with excellent keyboard-first ergonomics for meeting notes, RFCs, runbooks, and shared scratchpads.

The de facto dashboard of observability: Grafana is the open-source frontend that turns the data stores you already run into interactive graphs. It does not store metrics itself; it connects to the data stores you already run and turns their contents into interactive dashboards. Supported sources number over 150 via plugins: Prometheus, Loki, Tempo, InfluxDB, Elasticsearch, MySQL, PostgreSQL, Microsoft SQL Server, AWS CloudWatch, Azure Monitor, Google Cloud Monitoring, and many more. Dashboards are built from a large library of panel types (time series, heatmaps, tables, gauges, logs) with template variables for reusable, parameterized views. Unified alerting evaluates rules against any connected data source, not just Prometheus, and routes notifications to Slack, PagerDuty, email, and other channels with grouping and silencing - unlike Prometheus Alertmanager, a single rule can combine a Loki log pattern, a PostgreSQL query result, and a CloudWatch metric. Dashboards serialize to JSON and data sources configure via provisioning files, so the entire observability setup can live in Git and deploy repeatably across environments. Explore mode adds ad-hoc querying outside dashboards, with split view for correlating a metric spike against the matching log lines, and access control spans organizations, teams, folder permissions, and OAuth, LDAP, and SAML integration. Written in Go and TypeScript, AGPL-licensed. Self-hosting gives you unlimited users, dashboards, and queries at flat hosting cost, without Grafana Cloud's usage-based pricing.

Blast off into productivity space with Rocket.Chat SIX, the ultimate team collaboration cosmos! Imagine a place where your messages, tasks, and projects all live in harmony, orbiting around your team's efficiency like a well-organized galaxy. This isn't just any old chat platform; it's a customizable universe where you're the master of your data domain, with the power to tweak, integrate, and innovate to your heart's content. Ready to provide stellar customer service? Engage with your clients in a way that's so contextually on-point, they'll feel like you're mind-reading across the cosmos. Plus, with a chat engine that's like a gravitational pull for user engagement, your app or website will become the center of your users' universe. And for the security-conscious space cadets, fear not! Rocket.Chat SIX is locked down tighter than a spaceship hatch, with end-to-end encryption and a buffet of deployment options to satisfy your security appetite. All this, hosted on RepoCloud, where the cost is as lightweight as zero-gravity. So why settle for a terrestrial tool when you can have a celestial experience? Rocket.Chat SIX: because your team deserves to collaborate in a universe that's light-years ahead!

World Monitor replaces twenty or more browser tabs by fusing geopolitical, military, financial, and infrastructure signals onto a single interactive canvas built with TypeScript, Vite, globe.gl with Three.js for the 3D globe, and deck.gl with MapLibre GL for the flat map. World Monitor ingests live data from 530 upstream sources including ACLED and UCDP for conflict events, OpenSky Network for military and civilian aircraft, AISStream for vessel positions, NASA FIRMS for satellite fire detection, USGS for earthquakes, and FRED, IMF, BIS, and Finnhub for macroeconomic and market data. The Country Instability Index v8 computes real-time stress scores across 31 Tier-1 nations, while the finance radar tracks 29 stock exchanges, commodities, and cryptocurrency with a 7-signal market composite. Six specialized dashboard variants — World, Tech, Finance, Commodity, Energy, and Happy — deploy from a single codebase. AI summarization runs locally through Ollama and LM Studio integration or optionally via Groq and OpenRouter cloud providers, with Transformers.js powering browser-side inference. The platform supports 26 languages with native-language feeds and RTL layout, and provides MCP server integration for AI agent connectivity. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.

With over 37,800 GitHub stars and active development since its first release in 2008, ERPNext is the most-starred open-source ERP system — delivering accounting, inventory management, manufacturing, CRM, project tracking, asset management, HR, and point-of-sale capabilities through a unified web interface built on the Frappe Framework's metadata-driven architecture. The accounting module handles multi-company consolidation, multi-currency transactions, tax templates for GST and VAT, bank reconciliation, and automated journal entries with real-time profit and loss, balance sheet, and cash flow reporting. Manufacturing covers production planning with multi-level bill of materials, work order scheduling, capacity planning, subcontracting, and quality inspection at each production stage. Inventory tracks stock across multiple warehouses with batch and serial number tracing, automatic reorder levels, landed cost calculations, and perpetual inventory valuation using FIFO or moving average methods. The CRM module manages leads, opportunities, and customer communication with email integration, while project management tracks tasks, timesheets, and Gantt-based scheduling with budget controls. Custom applications extend functionality through the Frappe ecosystem without forking the core codebase, and the REST API enables integration with payment gateways, shipping providers, and third-party services. Deployable via Docker Compose or the bench CLI tool with MariaDB and Redis. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPL-3.0 licensed.

Every microservice has to find the others and learn its own settings, and Nacos is the discovery and configuration platform that answers both needs from a single server. Producers register instances with names, addresses, weights, and metadata, and consumers look services up or subscribe to changes, so a fresh instance receives traffic without hand-edited load balancer rules. Health checks drop dead instances from discovery results, while weight controls in the console shift traffic gradually during a rollout or drain a node before maintenance. Configuration lives apart from code: publish properties and YAML under a Data ID and Group, split environments with namespaces, and subscribed clients apply changes within seconds. History keeps every published version, so a typo is recoverable: rollback republishes an earlier value, and listener queries show which clients picked the change up. Gray releases push a new value to a chosen slice of instances first, so a risky flag reaches a fraction of the fleet before the rest. The registry covers AI building blocks too: MCP servers register their tools, prompts and skills carry versions and visibility, and agents publish discovery cards that gateways look up like any service. Spring Cloud, Dubbo, and Kubernetes workloads plug in through SDKs for Java, Go, Python, and other languages; run one standalone node for development or a Raft-backed cluster for production. 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.

Roughly 43% of all websites and over 60% of the CMS market run on WordPress - the GPL-licensed platform that scales from a personal blog to publishing operations and WooCommerce stores. The Gutenberg block editor composes pages from reusable blocks, and full site editing extends block control to headers, footers, and templates; tens of thousands of plugins and themes cover essentially every capability a site might need, from SEO and caching to membership and e-commerce. WordPress 7.0 "Armstrong" marks the platform's biggest structural update since Gutenberg itself: a React-based DataViews admin replaces the legacy list tables with instant filtering, a provider-agnostic AI Client API ships with connectors for OpenAI, Anthropic, and Google, media processing moves into the browser via WebAssembly, and a universal Font Library manages typography across block, hybrid, and classic themes with local hosting for GDPR compliance. New Breadcrumbs, Icons, and lightbox Gallery blocks reduce plugin dependence, and server-side PHP block registration simplifies development. The REST API and WP-CLI make it automatable end to end. Self-hosting is what WordPress was designed for: your content, database, plugin choices, and upgrade schedule stay entirely under your control, free of wordpress.com plan limits.

Backed by 56,000+ GitHub stars and over 240 million Docker pulls, LiteLLM delivers the open-source AI gateway trusted by Netflix, Lemonade, Rocket Money, and thousands of engineering teams to route every LLM request through one unified API. The Rust-core gateway adds sub-millisecond overhead per request with 8ms P95 latency at 1,000 RPS, 15x throughput improvement and 11x lower memory footprint compared to Python-only proxies. A single OpenAI-compatible endpoint connects to 100+ providers and 1,800+ models spanning OpenAI, Anthropic, Google Gemini, AWS Bedrock, Azure OpenAI, Vertex AI, Hugging Face, vLLM, Nvidia NIM, Ollama, and Mistral with day-zero support for new model releases. The Auto Router V2 classifies request complexity across four tiers using rule-based scoring, semantic keyword matching, and adaptive Thompson sampling to route each request to the most cost-effective model without API calls or training data. Virtual API keys enable multi-tenant governance with per-team, per-user, and per-project cost tracking, budget caps with automatic fallback rerouting, and role-based access control. Built-in guardrails provide PII masking, prompt injection detection, and model-graded evaluation before requests reach providers. The Agent Gateway extends routing from model calls to agent workflows with MCP server integration. Observability integrates with Langfuse, Arize Phoenix, OpenTelemetry, and MLflow for complete request tracing. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

NanoClaw delivers a radically simple alternative to OpenClaw — a single Node.js process and a handful of files that provide the same core functionality with true container-level security isolation. Agents execute inside Docker containers on Linux or Apple Containers on macOS, where even root access inside the sandbox cannot reach the host filesystem. The platform natively runs Claude Code via Anthropic's official Claude Agent SDK, with drop-in alternatives including OpenAI Codex, OpenRouter via OpenCode, Google, DeepSeek, and local open-weight models via Ollama — configurable per agent group. Multi-channel messaging connects WhatsApp, Telegram, Discord, Slack, Microsoft Teams, iMessage, Matrix, Google Chat, Webex, Linear, GitHub, WeChat, and email via Resend, installed on demand through skill commands. Each agent group receives its own CLAUDE.md memory file, isolated filesystem, container sandbox, and session state — a prompt injection in one group cannot exfiltrate data from another. The OneCLI Agent Vault handles credentials so agents never hold raw API keys, while approval-gated self-modification allows agents to request new packages or MCP servers that administrators must authorize. Scheduled tasks run recurring jobs inside containers with message delivery back to users. The setup script handles dependencies, authentication, and container configuration through Claude Code conversation. Deploy on any Docker-capable Linux server. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Upload a report, ask a "what if" question in plain language, and MiroFish builds a small simulated society that plays out the answer before you commit to a decision. It reads your seed documents, whether news, policy drafts, financial signals, or a novel, and extracts entities and relationships into a GraphRAG knowledge graph. Entities from the graph become agents with a profession, a biography, and interest tags, and the app estimates simulation rounds from the simulated time span, with a custom mode for shorter runs. Agents post and react on two simulated platforms at once, a feed-style plaza and a topic community, while a live monitor tracks rounds, elapsed simulated time, and actions. A ReportAgent then plans an outline and writes the prediction report section by section with the InsightForge, PanoramaSearch, QuickSearch, and InterviewSubAgent tools. Afterward you can keep questioning the ReportAgent, chat with any individual agent, or send a survey question to a selected group and read their answers. Typical uses include rehearsing public relations responses, testing policy drafts against likely reactions, and exploring alternate endings for a story. The interface switches between English and Chinese, and you bring your own model: any OpenAI SDK compatible LLM endpoint works, Zep Cloud stores agent memory, and the project suggests starting under 40 rounds because runs consume many tokens. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.

OmniRoute is an AI gateway, aggregating 338 LLM providers including OpenAI, Anthropic Claude, Google Gemini, DeepSeek, Kimi, MiniMax, and GLM into a single OpenAI-compatible endpoint at localhost:20128. The gateway catalogs over 1,200 models across 90 free-tier providers and 40 free-forever providers, automatically rotating through tier-1, tier-2, and tier-3 fallback chains when any provider exhausts its quota or returns errors. RTK plus Caveman stacked token compression reduces eligible context by 15 to 95 percent before forwarding requests, cutting API costs dramatically without degrading output quality. OmniRoute exposes its full routing engine through a built-in MCP server with 104 tools across 31 scopes over stdio, HTTP, and SSE transports, plus an A2A protocol server with six autonomous agent skills and JSON-RPC 2.0 streaming. The gateway integrates directly with Claude Code, Cursor, GitHub Copilot, Codex CLI, OpenCode, and Cline through standard base-URL configuration. Seventeen routing strategies include latency-optimized, cost-minimized, and auto-scoring modes that evaluate candidates on success rate, context fit, model fitness, quota state, and circuit-breaker health. The Next.js dashboard provides real-time provider status, usage analytics, combo chain configuration, and model catalog browsing via a responsive PWA. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

3X-UI is the most popular open-source Xray management panel, providing a full-featured web interface for deploying and monitoring proxy and VPN protocols on Linux servers. The Go backend manages Xray-core instances supporting VLESS, VMess, Trojan, Shadowsocks, WireGuard, Hysteria2, HTTP, SOCKS, Dokodemo-door, and TUN inbounds across TCP, mKCP, WebSocket, gRPC, HTTPUpgrade, and XHTTP transports secured with TLS, XTLS Vision, and REALITY. The Clients page tracks each user with individual traffic quotas, expiration dates, concurrent connection limits, and live online status indicators, while one-click share links, QR codes, and a built-in subscription server distribute configurations in multiple output formats. The multi-node architecture manages and scales deployments across multiple servers from a single panel instance. The Panel Settings page configures listen address, port, URI path, session duration, trusted proxy CIDRs, authentication, and Telegram bot integration for remote monitoring and management alerts. Outbound routing supports WARP, NordVPN, custom rules, load balancers, and proxy chaining. Xray Configs provides template-level control over the core configuration, while the API Docs page exposes a complete RESTful API with in-panel Swagger documentation. Data persists in SQLite by default or PostgreSQL for larger deployments, with database export and import from the panel. Fail2ban integration enforces per-client IP limits. On RepoCloud, deploy 3X-UI on a dedicated VPS with Docker, root SSH access, and complete control over your proxy infrastructure, all under the GPL-3.0 license.

New API is a Go-powered LLM gateway that funnels over 40 AI providers, from OpenAI and Anthropic to Google Gemini, Azure, AWS Bedrock, DeepSeek, and Mistral, through a single OpenAI-compatible endpoint with intelligent routing and enterprise cost controls. Bidirectional format conversion translates between OpenAI Chat Completions, Claude Messages, and Gemini GenerateContent APIs transparently, so clients call any provider using their preferred format while the gateway handles the rest. Routing logic supports weighted random channel selection, priority-based failover, and automatic retry on provider errors to maximize uptime. The React admin dashboard shows usage charts, token consumption tracking, per-model cost breakdowns, and real-time request monitoring. Multi-tenant architecture includes three role levels, token-based authentication, per-user quota management, and a three-phase billing system with tiered pricing via a custom expression language. Multimodal support covers text completion, vision, embeddings, text-to-speech, speech-to-text, image generation, and creative task providers like Midjourney-Proxy and Suno-API. The interface ships in five languages including English, Chinese, Japanese, and French. Docker deployment runs with SQLite or MySQL for persistence. 45,000+ GitHub stars. AGPL-3.0 licensed.