BillionMail
With over 15,000 GitHub stars accumulated since its February 2025 launch, BillionMail delivers the rare combination of a production mail transfer agent and a full email marketing suite in a single self-hosted package — eliminating the monthly per-subscriber fees charged by Mailchimp, SendGrid, and similar platforms. The Go-based architecture bundles Postfix for SMTP transmission, Dovecot for IMAP and POP3 mailbox access, Rspamd for intelligent spam filtering and greylisting, and RoundCube for browser-based webmail, all orchestrated through Docker Compose with PostgreSQL for persistent storage and Redis for queue management and caching. The marketing engine supports unlimited subscriber lists with tag-based segmentation, scheduled campaign sends, A/B subject line testing, and both HTML and drag-and-drop visual template editors for crafting responsive emails without coding. Real-time analytics dashboards track sent volume, deliverability rate, open rate, click-through rate, and bounce reasons, while the platform provides step-by-step DNS record configuration wizards for SPF, DKIM, and DMARC to maximize inbox placement. A transactional email API exposes REST endpoints for single and batch sending, enabling integration with CRM systems, e-commerce platforms, and custom applications. Auto-provisioned free SSL certificates, Fail2ban brute-force protection, and privacy-first architecture with zero third-party tracking ensure secure operation. The platform installs in under eight minutes via a single shell script and supports SMTP on port 25, SMTPS on 465, submission on 587, IMAP on 143/993, and POP3 on 110/995. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPLv3 licensed.
Omnigent
Open-sourced by the Databricks AI team under Apache 2.0 and reaching over 8,500 GitHub stars within two months of launch, Omnigent introduces the meta-harness concept: a common orchestration layer that sits above existing AI coding agents and makes them interoperable parts of a governed, collaborative system. The platform wraps Claude Code, Codex, Cursor, OpenCode, Hermes, Pi, and any custom agent defined in a simple YAML configuration file into sandboxed sessions with a uniform API, then exposes each session through the terminal, a web UI, a native desktop application, mobile interfaces, and a REST API. Built-in multi-agent workflows include Polly, a coding orchestrator that delegates tasks to parallel sub-agents in separate git worktrees and routes each diff to a reviewer from a different vendor, and Deep Research, which plans sub-queries, searches the live web through MCP servers, reads full pages, and cross-checks claims across independent sources. Contextual security policies go beyond static allow/deny rules by maintaining per-session state to enforce spend caps, model routing, approval gates for destructive actions, PII blocking, and repository-scoped write restrictions across server-wide, per-agent, and per-session levels. The OS sandbox restricts filesystem and network access while intercepting egress requests to inject credentials only on approved calls. Cloud sandbox providers including Modal, Daytona, E2B, CoreWeave, Kubernetes, and Databricks launch disposable execution environments per session. 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.
OctoPrint
Over a million active instances make OctoPrint the standard web interface for consumer 3D printers - Gina Häußge's Python application, the center of the printing world since 2012. It talks to your printer over USB serial and turns every browser into a control panel: upload, organize, and start G-code prints; watch hotend and bed temperature graphs in real time; drive the print head manually; adjust feed rate, flow, and fan speed mid-print; and hit an emergency stop if things go wrong. The G-code visualizer renders the current layer in sync with the job, and a connected webcam adds a live feed plus automatic timelapse recording of every build. What keeps OctoPrint ahead is its plugin ecosystem - 300+ community plugins installable from the built-in manager. Highlights include Obico's AI spaghetti detection that pauses failed prints automatically, OctoEverywhere for tunnel-based remote access, Bed Level Visualizer's 3D mesh of your bed surface, PrintTimeGenius for accurate time estimates, Exclude Region to abandon one failed object mid-print while others continue, and Firmware Updater to flash Marlin or Klipper without SD-card shuffling. Event hooks fire notifications when prints finish or fail, and a full REST API supports slicer integration and custom automation. AGPL-licensed.
HumHub
Workplace and Yammer's pattern on your own server, with GDPR compliance by construction rather than contract: HumHub is an open-source enterprise social network from Germany. Built in PHP on Yii2, it organizes everything around four concepts. Users get rich profiles with follows and interactions. Spaces are the structural unit - rooms for departments, projects, events, or clubs, with per-Space permissions, notification settings, and email summaries, and operators can auto-map users into the right Spaces. Content covers posts, wiki pages, photos and video, events, and tasks, with multi-level comments, versioning, archiving, moderation reporting, and filterable full-text search across everything. Modules make it a platform: roughly 80 install-and-activate extensions including Calendar, Wiki, Polls, Tasks, Gallery, News, direct-message Mail, OnlyOffice document editing, Advanced LDAP, SAML and JWT SSO, a RESTful API, mass user import, Translation Manager, and a Theme Builder with custom pages - every one optional and toggleable at runtime. That module economy is why HumHub serves such varied deployments: corporate intranets, city governments, universities, political parties, and nonprofits all configure the same core differently. Requirements are a plain LAMP stack - PHP 8.1+ and MySQL/MariaDB - making it one of the easiest community platforms to operate long-term.
QuestDB
Powering trading floors at firms processing millions of market data events per second and trusted by organizations including Airbus, Yahoo, and Copenhagen Atomics, QuestDB has earned over 17,000 GitHub stars as the time-series database that refuses to make you choose between ingestion speed and query latency. The column-oriented, time-partitioned storage engine processes millions of rows per second on ingest through write-ahead logging with instant durability, while SIMD-accelerated parallel execution returns analytical queries over billions of rows in milliseconds. Time-series SQL extensions add ASOF JOIN for point-in-time lookups across tables with misaligned timestamps, SAMPLE BY for downsampling at arbitrary time intervals, LATEST ON for last-value queries, and WINDOW JOIN for sliding window aggregations — all through standard SQL syntax accessible via the PostgreSQL wire protocol, REST API, or the QuestDB Wire Protocol (QWP) that streams Apache Arrow at 220 million rows per second. Multi-tier storage automatically moves data from the WAL through native columnar format to Parquet files on S3-compatible object storage, keeping hot data fast and cold data portable without manual tiering. The built-in web console provides an interactive SQL editor with syntax highlighting, autocomplete, and charting for quick data exploration. Views, materialized views, and n-dimensional arrays support real-time analytics, while native Parquet export enables direct integration with Python, DuckDB, and AI/ML frameworks. 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.
Krayin CRM
Krayin CRM gives sales teams a visual Kanban pipeline where leads flow through configurable stages — new, contacted, qualified, proposal, won, lost — with deal values tracked per stage, drag-and-drop transitions, and AI-powered document import that extracts contact details from uploaded PDFs, DOCs, and images without manual data entry. Built on Laravel 12 with a Vue.js frontend and MySQL database, the platform delivers complete customer lifecycle management through a two-stage contact model separating unqualified Leads from qualified Persons linked to Organizations, with a unified timeline displaying associated activities, notes, emails, and deals. The activity module schedules calls, meetings, and tasks on a drag-and-drop calendar with reminders and team assignment. A built-in product catalog supports line-item quoting with pricing and quantities. Email integration connects via SMTP, IMAP, and SendGrid parsing, linked to leads and contacts automatically. Workflow automation triggers actions on conditions and pushes events to external systems via webhooks. The dashboard visualizes pipeline performance, top customers, top products, and email engagement with pie charts and trend widgets. Custom attributes add text, number, date, boolean, and dropdown fields to any entity. Role-based ACLs manage team permissions per module. Extensions add multi-tenant SaaS, WhatsApp lead generation, and VoIP calling. Deploy via Docker Compose. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.
Neko
With over 21,000 GitHub stars and six years of steady development through version 3.1.0, Neko transforms any Docker container into a fully interactive browser or desktop environment streamed to web browsers via WebRTC with sub-300-millisecond glass-to-glass latency. The Go backend captures X server display frames using the Pion WebRTC library while the Vue.js frontend renders the remote session with native audio synchronization, delivering a significantly smoother experience than Apache Guacamole or noVNC which rely on image-over-WebSocket approaches. Multiple users simultaneously view and collaboratively control the same session with real-time input synchronization and host-managed control passing between participants. Pre-built Docker images cover Firefox, Chromium, Google Chrome, Tor Browser, Brave, Vivaldi, and Microsoft Edge alongside full desktop environments including XFCE and KDE for running any Linux application. Neko Rooms provides multi-tenant deployment with a REST API for programmatic room provisioning, while Neko Apps extends the platform with additional containerized applications beyond browsers. Sessions persist on the server independently of client connections — close your laptop, reconnect from your phone, and resume exactly where you left off. Optional VPN and Tor integration routes traffic through encrypted tunnels for privacy-sensitive browsing. RTMP broadcasting streams sessions to external platforms. The embeddable client supports iframe integration for custom portals and applications. 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.
Misskey
With 11,000+ GitHub stars and over 1,291 releases since 2016, Misskey is the most feature-rich open-source microblogging platform in the Fediverse — federation-first social networking with capabilities that go far beyond simple status updates. The TypeScript and Vue 3 frontend delivers a highly customizable interface with drag-and-drop widget layouts, switchable themes, per-user custom CSS, and AiScript-powered plugins that transform every instance into a unique social experience. ActivityPub federation enables seamless interaction with Mastodon, Pixelfed, PeerTube, and any ActivityPub-compatible platform across the decentralized network. Emoji reactions let users respond with custom instance emojis instead of simple likes, while Misskey Flavored Markdown adds animated text effects, sparkle decorations, and rich formatting to posts. The built-in Drive provides personal cloud file management with folder organization for images, videos, and audio — eliminating the need for external storage services. Antennas create custom filtered timelines based on keywords, users, or criteria for monitoring specific topics. Channels offer topic-specific feeds separate from the main timeline. Pages enable users to build personal websites directly within their instance. Clips save and organize posts into curated collections. The Node.js backend scales with PostgreSQL for persistence, Redis for caching, and optional S3-compatible storage for media. Docker Compose deployment provisions the complete stack including the database and cache in under 15 minutes. 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.
Docmost
Confluence and Notion both want your team's documentation in their cloud; Docmost, an open-source collaborative wiki platform, keeps it on your server. The centerpiece is a Notion-style block editor with CRDT-based real-time collaboration: multiple people edit the same page simultaneously and changes merge without conflicts or overwrites. Content lives in spaces - per team, project, or department - with nested page trees, role-based permissions, groups, inline comments, page history with restore, and full-text search across everything. The editor covers tables, code blocks, callouts, KaTeX math, and file attachments, and diagramming is built in rather than bolted on: Mermaid, Draw.io, and Excalidraw all render inside pages, alongside embeds for Airtable, Loom, Miro, and more. Migration paths include Notion, Markdown, HTML, and ZIP archive imports (Confluence, PDF, and DOCX importers ship in the Enterprise edition, along with SSO via SAML/OIDC/LDAP and MFA). The stack is TypeScript with PostgreSQL and Redis, deploys via Docker Compose, runs in air-gapped environments with no external dependencies, and is translated into 10+ languages. The AGPL-3.0 community edition carries no per-seat fees; the project has passed 20,000 GitHub stars since its 2024 launch.
Webstudio
Webstudio delivers a professional-grade visual website builder that outputs semantic HTML and clean CSS without inline style pollution or JavaScript-heavy render paths. The live canvas editor provides direct manipulation of all CSS properties — flexbox, grid, spacing, typography, transforms, and filters — with real-time preview across responsive breakpoints. The component system supports reusable instances with variants and overrides, while design tokens maintain consistent colors, fonts, and spacing across the entire site. Data bindings connect to external content sources through native integrations with Strapi and Supabase, plus a generic CMS interface for any REST API backend. The Scroll Timeline API powers animations at 120 FPS off the main thread, with presets for rotate, scale, translate, opacity, color, and filter effects. Projects build as dynamic Remix applications with server-side rendering or export as static HTML, CSS, and JavaScript files. The Webstudio CLI generates Docker-ready builds that run a Node.js server on port 3000, with Nginx reverse proxy configuration for SSL termination via Let's Encrypt. The builder requires minimum 1 GB RAM and 1 CPU core for Docker builds. MCP integration enables AI agents to create and modify websites programmatically. On RepoCloud, deploy Webstudio projects on a dedicated VPS with root SSH access, persistent storage, and complete control over your hosting, custom domains, and deployment pipeline, all under the AGPL-3.0 license.
Coder
With over 14,000 GitHub stars and enterprise adoption by security-conscious organizations, Coder transforms how development teams provision, manage, and secure their coding environments. Every workspace is defined as a Terraform template, meaning infrastructure engineers can standardize development environments across EC2 instances, Kubernetes pods, Docker containers, or any combination, while developers get self-service provisioning that launches in seconds rather than days of manual setup. The WireGuard-based networking layer establishes encrypted tunnels between developer machines and remote workspaces, providing low-latency access without exposing ports or configuring VPN concentrators. Automatic idle detection shuts down unused workspaces after configurable periods, directly reducing cloud compute costs for organizations running hundreds of developer environments. The Coder Agents feature introduces native AI coding capabilities where the agent loop executes entirely within the control plane on self-hosted infrastructure, keeping LLM API credentials out of individual workspaces and eliminating credential exfiltration risks. Centralized model governance allows platform teams to approve specific AI providers and models, set per-user spend limits, and maintain complete audit logs of all prompts, tool calls, and agent activity. IDE integration supports VS Code through a dedicated extension, JetBrains IDEs via Gateway and Toolbox plugins, and browser-based code-server for web access. The template registry provides pre-built configurations for common development stacks. DevContainer support builds environments from standard devcontainer.json specifications. Deploy 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.
Draw a UI
Sketch a wireframe, get working code: Draw a UI turns hand-drawn layouts into web interfaces. It pairs the open-source tldraw canvas with an OpenAI vision model: you sketch a layout - boxes, labels, buttons, arrows, whatever communicates the idea - select the drawing, and click Make Real. The app snapshots your selection as a PNG, sends it to the vision API with instructions to return a single HTML file styled with Tailwind CSS, and renders the result in an iframe directly on the canvas next to your sketch. The loop is iterative: annotate the generated prototype or redraw parts of it, select both the sketch and the previous result, and generate again - the model receives the earlier HTML as context and produces an updated version. Built by Figma engineer Sawyer Hood as one of the first viral GPT-4 Vision demos and the basis for tldraw's "Make Real", it is a Next.js app that runs against your own OpenAI API key. Self-hosting matters here: the upstream demo ships without authentication, so a private deployment keeps your API key from being drained by strangers. MIT-licensed.
ArchiveBox
Backed by 27,700+ GitHub stars and actively developed with the v0.9.x architectural overhaul introducing an event-driven plugin ecosystem, ArchiveBox delivers the open-source self-hosted web archiving platform that preserves websites, bookmarks, social posts, media, source code, and research material in durable formats before link rot, platform shutdowns, and censorship erase them permanently. Feed it URLs one at a time or schedule automated imports from browser history, RSS feeds, Pocket, Pinboard, Instapaper, Wallabag, Shaarli, JSON, CSV, HTML bookmark exports, and browser extension captures. Each snapshot stores redundant copies as original HTML, rendered single-file HTML via SingleFile, full-page PDF, screenshot PNG, WARC archive, article text via Readability, favicons, HTTP headers, media files via yt-dlp, git repository clones, and structured metadata in SQLite. The Docker Compose deployment bundles Chrome, wget, curl, yt-dlp, SingleFile, and Readability parsers with automatic dependency management and isolation. Interact through the self-hosted web UI with search, tagging, and admin controls, the comprehensive CLI for batch operations, the REST API for programmatic access, or the Python API for custom integrations. The new abx-plugins system enables community extractors with per-plugin configuration, while the append-only-log architecture provides resumable crawls and audit trails. S3, B2, and Google Cloud storage backends sync archives to remote storage via rclone. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.
Ory Hydra
Ory Hydra is an OpenID Certified OAuth 2.0 and OpenID Connect provider that plugs into any existing user database or authentication system through a headless consent and login bridge, letting you own your authorization infrastructure without rebuilding identity management from scratch. The Go binary ships at under 15MB with zero system dependencies and exposes two distinct API surfaces: a public endpoint on port 4444 handling authorization code flows, token exchanges, PKCE challenges, device authorization grants per RFC 8628, and OpenID Connect discovery, plus an admin endpoint on port 4445 managing client registration, token introspection, consent session lifecycle, and JWKS rotation. Access tokens can be issued as opaque reference tokens or signed JWTs for stateless validation at resource servers, while refresh token rotation, token revocation per RFC 7009, and pairwise subject identifiers provide granular security controls. Persistent storage spans PostgreSQL, MySQL, and CockroachDB with automatic schema migrations, and the architecture supports horizontal scaling behind load balancers with shared database state. Dynamic client registration per RFC 7591 enables automated provisioning, and the OAuth 2.0 Threat Model security considerations are implemented as default behaviors rather than optional add-ons. Trusted by OpenAI and other internet-scale platforms. Helm charts and Docker Compose quickstarts provide production-ready deployment paths alongside the broader Ory ecosystem including Kratos for identity management, Oathkeeper for zero-trust API proxying, and Keto for fine-grained permissions. 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.
big-AGI
big-AGI is an open-source generative AI workspace that provides a unified, local-first interface for orchestrating multi-model reasoning, automated code execution, and custom persona workflows across private infrastructure. Users query multiple large language models simultaneously through the Beam scatter-gather engine, which prompts independent AI systems in parallel, compares candidate completions side by side, and merges optimal passages into a single refined response. Knowledge workers assemble tailored AI personas equipped with specialized system instructions, custom temperature settings, and predefined document context to handle domain-specific tasks ranging from architectural design reviews to legal contract analysis. The application renders rich multimedia outputs including interactive Mermaid sequence diagrams, LaTeX mathematical formulas, syntax-highlighted code blocks with live execution previews, and AI-generated image generation canvases. Teams integrate local inference servers like Ollama and LocalAI alongside commercial API endpoints to route confidential datasets strictly through internal networks while monitoring per-prompt token usage and operational latency. Users attach complex PDF documents, spreadsheets, and source code repositories for automatic parsing and semantic retrieval, while local-first storage engines ensure private chat transcripts and custom presets remain encrypted on host drives. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.
Languagetool
Grammar, punctuation, and style errors a dictionary lookup can't see: LanguageTool is open-source proofreading powered by a Java rule engine covering English, German, Spanish, French, Portuguese, Dutch, and 25+ other languages. Self-hosting the HTTP server is how you get Grammarly-class checking without sending every sentence you write to a third party - a real concern when the text being proofread is confidential email, legal drafts, or unreleased documentation. Your instance exposes the standard /v2/check API, so the official ecosystem plugs straight in: browser extensions for Chrome and Firefox accept a custom server URL, and integrations exist for VS Code, LibreOffice, Obsidian, Vim, Emacs, and many editors. Notably, self-hosting restores free browser-extension checking that the hosted service moved behind a premium subscription - your server, no character limits, no paywall. Detection quality is tunable: optional n-gram datasets (multi-gigabyte language models for en, de, es, fr, nl) teach the engine word-order and confusion-pair errors like there/their and brakes/breaks, and a fastText model improves automatic language identification. Everything runs offline once models are downloaded. The core is LGPL, the API is documented with Swagger, and rules are community- maintained and constantly expanding.
RustFS
Tools and applications that already speak S3 can use RustFS as their storage backend, so backup jobs, data pipelines, and services keep working while the data stays on infrastructure you control. A built-in web console on port 9001 manages buckets, object uploads and downloads, access keys, users, groups, and IAM policies, with a status page for cluster health, capacity, and scanner activity. Versioning, Object Lock retention, bucket quotas, and server-side encryption with Vault or AWS KMS backends protect objects once they land. Lifecycle rules expire or transition data, and tiering moves cold objects to remote targets such as Amazon S3 or Wasabi. Bucket replication and site replication keep clusters in sync, and event notifications call webhooks when objects change. Single-node mode suits a lab or small server, while distributed mode adds erasure coding, bitrot protection, background healing, and pool expansion or decommissioning as capacity grows. Sign-in works with local users, OIDC single sign-on, or OpenStack Keystone, and FTPS and WebDAV are available by default, with SFTP and the Swift API as opt-in builds. A preview of S3 Tables exposes an Iceberg REST catalog for tools such as DuckDB and PyIceberg, and a documented migration path moves existing MinIO deployments across. Typical uses include backups, container registries, logs and traces, data lakes, and AI training sets. 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.
InvenTree
InvenTree is an inventory management system for electronics manufacturers, makerspaces, and small-to-medium businesses. The hierarchical part categorization system organizes components into unlimited nested categories, while stock items tracked across cascading locations and sub-locations provide instant visibility into current inventory levels, with optional serial number tracking for individual item traceability and acceptance testing. Intelligent BOM management calculates sub-part requirements, validates availability against current stock, supports multi-format BOM upload including KiCad integration, and generates detailed bills of materials with full database enrichment. Build orders consume BOM-allocated stock to produce assembled parts with step-by-step work order tracking, while purchase orders manage supplier relationships with pricing history, lead times, and automatic stock receipt processing. The modern React frontend built with Mantine, TanStack Query, and Zustand provides responsive data tables, tree-select navigation, a preview drawer, and a snippet editor. The extensible plugin system supports 19 mixin types including BarcodeMixin for scanner integration, LabelPrintingMixin for Zebra and Brother printers, AppMixin for custom database tables, and ScheduleMixin for periodic background tasks. Companion mobile apps on Android and iOS provide barcode scanning and stock operations in the warehouse. Docker Compose deploys with PostgreSQL, MySQL, or MariaDB backends behind any reverse proxy. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.