Starred by over 6,500 users on GitHub and trusted by organizations including Toyota, CTFd has been the leading open-source platform for hosting cybersecurity competitions since 2015, providing everything needed to run professional Capture The Flag events through a clean web-based administration panel without touching a database query. The framework supports both individual and team-based competitions with automatic tie resolution, configurable score freezing, and scoregraphs comparing the top teams with detailed progress tracking. Challenge creation offers static and regex-based flags, dynamic scoring that adjusts point values based on solve count, unlockable hints purchasable with points, file attachments uploaded to local storage or Amazon S3-compatible backends, and challenge attempt limits with automatic bruteforce protection. Version 3.8 introduced challenge logic fields controlling flag submission behavior with any, all, and team modes, integrated dynamic scoring into the standard challenge type, participant ratings and reviews on challenges, and admin-stored challenge solutions viewable after competition. The Markdown-based content management system enables custom pages for rules, FAQs, and resources, while SMTP and Mailgun integration handles email confirmation and password recovery. The plugin architecture supports custom challenge types, flag validators, and scoring algorithms, while the theme system provides complete visual customization. Import and export functionality preserves entire competition configurations for archival and reuse across events. 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.

With 16,100 GitHub stars and created by Solomon Hykes (co-founder of Docker), Dagger eliminates proprietary YAML DSLs from CI/CD by letting developers write pipelines as real programs in their preferred language — then executing them identically on a laptop, in GitHub Actions, in GitLab CI, or on any machine with a container runtime. The BuildKit-based Dagger Engine runs every pipeline operation inside OCI containers, constructing a directed acyclic graph where each node is cached by default, parallelized automatically, and produces bit-for-bit reproducible outputs regardless of execution environment. Native SDKs generated from the GraphQL API schema provide Go, Python, TypeScript, PHP, Java, .NET, Elixir, and Rust developers with full type safety, IDE autocomplete, and the ability to unit-test CI pipelines using the same testing frameworks as application code. The module ecosystem enables cross-language composition where a Python team can invoke a Go team's build functions without learning Go, while filesystems, secrets, git repositories, and network tunnels are passed between functions as strongly-typed objects. Pipeline operations cache at container-layer granularity with content-addressed deduplication, and the interactive REPL enables step-by-step pipeline debugging with live container inspection. Host dependencies are explicit and strictly typed, eliminating implicit environment coupling that causes "works on my machine" failures. 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.

Frappe LMS is a learning management system built on the same Frappe Framework that powers ERPNext. The 3-level course hierarchy organizes content into courses, chapters, and lessons supporting videos, PDFs, SCORM packages, and rich HTML content with heading, code block, and list formatting through the redesigned inline lesson editor. Batch management groups learners by course and duration with scheduled instructor-led live sessions through integrated Zoom and Google Meet, where learners see upcoming classes on their batch dashboard. The assessment engine supports single-choice, multiple-choice, and open-ended quiz questions alongside assignment submissions as PDFs or documents, with progress tracking monitoring completion rates and quiz performance across all enrolled courses. Certificate generation uses built-in templates or custom designs to validate course completion, while the job board connects certified learners with opportunities. Course monetization integrates payment processing to transform courses into revenue streams with financial tracking. Role-based access controls assign Instructor, Learner, Admin, and Manager permissions, while course package import and export enables sharing structured content between instances. The platform integrates with ERPNext HR and CRM modules through the Frappe ecosystem with RTL language support and notification slide-overs. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPLv3 licensed.

Zero unifies Gmail, Outlook, and IMAP accounts into a single AI-enhanced inbox with keyboard-driven navigation that matches premium email clients in speed. Backed by 10,000+ stars and positioned as the alternative to Superhuman, it keeps your email data in your own PostgreSQL database while LLM agents handle categorization, priority sorting, draft composition, and natural language mailbox queries. You choose whether models run locally or through cloud providers you control. The Next.js and React interface delivers customizable keyboard shortcuts for every action: reading, archiving, labeling, composing. A WorkflowEngine defines automated multi-step rules including label application, bulk archiving, and conditional routing based on sender, subject, or content analysis. Built on Drizzle ORM with Better Auth handling Google OAuth, styled with TailwindCSS and Shadcn UI components, the interface is polished without being bloated. MCP integration exposes email management tools to external AI assistants for programmatic inbox control through standardized protocols. The Nizzy CLI handles environment configuration, database synchronization, and development server orchestration. Deploys via Docker Compose with a single database initialization command. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Your Gmail, Google Workspace, or Outlook inbox, worked by an AI assistant: Inbox Zero sits on top of the account you already have. Its core idea is rules written in plain English - tell the assistant "label invoices and file the PDF to Drive" or "archive cold outreach unless they mention my company" - and it executes against every incoming message. Emails that need a response arrive with a pre-drafted reply written in your tone, learned from your email history and calendar context. Reply Zero tracks what you owe responses to and what you're waiting on; the Bulk Unsubscriber surfaces newsletters you never read (with read-rate analytics) for one-click unsubscribe-and-archive; the Cold Email Blocker auto-archives unsolicited pitches based on your own definition of "cold." Smart Filing routes attachments - receipts, contracts, PDFs - into the right Google Drive or OneDrive folder, and Slack/Telegram integration lets you read, draft, and triage without opening a mail client. Email analytics show top senders and volume trends. It is not a new email client: everything happens in your real mailbox using native filters. Self-hosting means your mail content and the LLM calls that process it run on infrastructure you control.

Spree Commerce provides a complete headless ecommerce backend where products, orders, payments, and promotions are managed through typed REST APIs with OpenAPI 3.0 specs and TypeScript SDKs providing autocomplete and type safety. Fifteen years of production history and 15,600+ GitHub stars back a mature ecosystem that ships a production-ready Next.js 16 storefront built with React 19 and Tailwind CSS 4, including multi-region URL routing and Stripe payments supporting Apple Pay, Google Pay, Klarna, and Affirm. Sales Channels model distinct contexts from a single instance: DTC storefronts, wholesale portals, mobile apps, and point-of-sale terminals, each with its own catalog, pricing, and checkout flow. The rules-based promotion engine supports coupon codes, multi-condition discounts, gift cards, and digital product fulfillment. Multi-warehouse inventory tracks stock across locations in real time with reservations and advanced order routing that splits shipments across fulfillment centers. B2B capabilities include customer-specific price lists, storefront access gating, wholesale portals with approval workflows, and quick order forms. The admin dashboard built with Tailwind CSS provides role-based permissions, product management, order processing with refunds, and scaffold generators for custom pages. BSD 3-Clause licensed with zero platform or transaction fees. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console.

Two decades of continuous development made Roundcube the standard-bearer of open-source webmail - a PHP IMAP client that gives any mail server a polished, application-like interface in the browser. It connects to whatever IMAP/SMTP stack you run - Dovecot, Postfix, a hosted mailbox - and delivers the full desktop-client experience: drag-and-drop message management, threaded conversation views, full MIME and HTML mail handling, find-as-you-type address book with groups and LDAP connectors, multiple sender identities, full-text search, and spell checking in dozens of languages. The default Elastic skin is genuinely responsive, working as well on a phone as a desktop, and the entire UI is skinnable. The plugin API is where deployments get shaped: managesieve exposes server-side filter management in the UI, enigma brings PGP encryption and signing via GnuPG, markasjunk trains spam filters, zipdownload batches attachments, password lets users change credentials, and attachment_reminder catches the classic forgotten-attachment email - among hundreds of community plugins. Built-in caching keeps large mailboxes fast, IMAP ACLs and shared folders support team setups, and XSS protection is engineered into the rendering pipeline. It scales from a single personal mailbox to unlimited users, backed by MySQL, MariaDB, PostgreSQL, or SQLite. GPL-licensed with regular security releases.

Built as a developer-first alternative to SendGrid, Mailgun, and Postmark, Posta delivers a complete self-hosted email infrastructure platform handling both outbound delivery and inbound reception through a single HTTP API with official SDKs for Go, PHP, and Java. The Go backend processes email through Redis and Asynq with automatic retries, priority queues, and async delivery while PostgreSQL stores templates, contacts, campaigns, and delivery analytics. Outbound features include versioned multi-language templates with variable substitution and stylesheet inlining, bulk campaigns with subscriber targeting and A/B testing per-variant metrics, scheduled timezone-aware delivery with draft/paused/cancelled lifecycle states, email address verification checking syntax, MX records, disposable domains, and role accounts, plus web view links with signed expiring URLs and one-click unsubscribe headers. The built-in SMTP receiver with TLS handles inbound email at your domains, parses messages and attachments, scores spam, and forwards structured payloads to your application via HMAC-verified webhooks with real-time SSE notification streams. The Vue-based dashboard manages templates, SMTP server pools, domains, contacts, API keys, campaigns, and email logs with dark and light mode support while admin-level platform metrics expose delivery rate trends, bounce rate graphs, and latency percentiles alongside Prometheus integration and daily health reports. Deploy via Docker with PostgreSQL and Redis. 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.

Browse trending titles, search anything, request it in two clicks: Jellyseerr gives Jellyfin, Emby, and Plex users a beautiful storefront for the media library. Born as the Overseerr fork that added Jellyfin and Emby support (the projects have since unified as Seerr), it handles the full request lifecycle - users authenticate with their existing media-server accounts, pick individual seasons or movies in a clean interface, and admins approve or decline from a simple queue, including on mobile. Approved requests flow straight to Sonarr and Radarr, which handle acquisition automatically, with support for separate 4K server instances. Regular library scans keep availability accurate, so users see instantly what already exists instead of requesting duplicates. A granular permission system controls who can request what - auto-approval for trusted users, quotas and limits elsewhere - and override rules adjust request routing by user, tag, or other conditions. Watchlist and blocklist functions curate discovery, notifications reach email, Discord, Telegram, Slack, Pushover, and Pushbullet, and both PostgreSQL and SQLite are supported. Localized into many languages, it turns "can you add this movie?" texts into a self-service system that runs itself.

Turn company knowledge into structured courses in minutes: ClassroomIO's AI course builder takes your documents, policies, or topic outlines and generates complete lessons with exercises using Gemini, GPT-4o, or Claude — then an in-lesson AI tutor helps employees study the material at their own pace. The SvelteKit 5 and Hono API architecture backs a platform purpose-built for employee compliance training, customer education, and partner certification programs. Programs group courses into cohorts with team management, progress tracking, and goal setting. Live Kahoot-style quizzes drive real-time engagement during training sessions with automatic scoring and leaderboards. Exercises support multiple question types with automatic grading for multiple choice and AI-assisted evaluation for open-ended responses — teachers review and override all AI decisions. Branded certificates with custom IDs reward course completion. Custom domain mapping through Cloudflare lets organizations serve their learning portal under their own brand. MinIO provides S3-compatible storage for documents and video uploads. The REST API and signed webhooks enable programmatic enrollment and completion tracking, while an MCP server on npm supports AI-native authoring workflows. An embeddable widget drops the course catalog onto any website. Better Auth handles sessions and OAuth with optional SSO. 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.

openGym is a self-hosted gym and body-weight tracker that plans your weekly routines, guides every set with pre-filled weights and rest timers, and keeps your training data on a server you control instead of inside a subscription app. Over 5,600 exercises come with animated demos, searchable by body part and the equipment you own, and you can add custom ones with your own photo or video. Progression follows a rule you pick per routine (linear, Greyskull LP, double, triple, or added time), and each target explains where it came from. Supersets, warm-ups, drop sets, rest-pause, timed planks, and cardio by time and speed all log properly, and plate math shows what goes on each side of the bar. A muscle map shows where your volume went, what is still recovering, and what went untrained, beside estimated one-rep maxes, a year-long heatmap, and body weight charted against your goal. Imports from FitNotes, Strong, and Hevy carry your history over. Several people can share one server, each with a private passkey profile, and an optional admin dashboard handles invite-only signup. An optional AI coach, off by default, drafts routines and suggests changes through your own Anthropic, OpenAI, Gemini, or Ollama endpoint, and nothing applies without your approval. The interface speaks 19 languages. 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.

Flowsint turns scattered OSINT leads, like a domain, a username, an email, or a crypto wallet, into one interactive graph that you expand with a right click. Drop an entity on the canvas, run an enricher, and the results appear as new nodes with their relationships already drawn in. Over 30 built-in enrichers cover subdomain discovery, WHOIS and historical records, DNS and ASN lookups, IP geolocation, username searches with Maigret and Sherlock, breach checks for emails and phone numbers, Gravatar profiles, website crawling for contacts and tracking codes, and Ethereum wallet transactions and NFT transfers. Chain enrichers into flows so each output feeds the next step, then replay the same flow on any entity of that type. Missing a source? Write an enricher template in YAML, or describe the API in plain language and let the built-in AI draft it, with API keys kept in an encrypted vault instead of config files. Custom entity types, aliases, tags, JSON import and export, and basic role-based access control make it workable for small teams, and an n8n connector pipes findings into alerts and reports. Double-click the canvas to add items fast, or alt-drag between nodes to link them. Every graph stays on your own server, and no default accounts exist. 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.

dyrector.io gives teams a visual web interface for deploying and managing containerized applications across Docker, Kubernetes, and Podman environments, replacing repetitive CLI commands and YAML editing with point-and-click configuration. Lightweight Go agents installed on target infrastructure communicate with the central TypeScript platform, enabling deployments to AWS, GCP, Azure, and on-premises servers without requiring infrastructure migration. Unified configuration screens eliminate redundant YAML editing across environments with support for all three container runtimes. Version management lets teams configure OCI-compatible container images once and deploy them as versioned releases with auto-generated changelogs and release notes. Multi-instance deployment enables simultaneous rollouts to multiple nodes with environment-specific configuration overrides, secret management, and instant test environment provisioning from any branch. The fine-grained RBAC system controls user access at project and environment levels, while audit logging tracks every deployment action. Registry integrations support Docker Hub, GitLab, GitHub, Google, and Azure container registries for image sourcing. ChatOps notifications integrate with Slack, Discord, and Microsoft Teams for deployment status alerts. Scheduled releases and workflow support enable automated deployment pipelines triggered by CI events via the REST API with JWT authentication. 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.

Point Emby at your movie, music, and photo libraries and it becomes a private streaming service: metadata and artwork arrive from TMDB and TVDB, everything lands in a polished browsable interface, and media transcodes on the fly whenever a client can't play the original format. The client reach is the selling point: native apps span Android TV, Apple TV, Google TV, Fire TV, Roku, LG and Samsung smart TVs, iOS, Android, Apple CarPlay, Android Auto, plus web browsers and desktop apps for Windows, macOS, and Linux, and DLNA devices are auto-detected for casting and remote control. Multi-user support gives each household member their own account, watch history, favorites, and recommendations, with genuinely capable parental controls: content restrictions, access schedules, time limits, and live monitoring with remote control of kids' sessions. Live TV works with hardware tuners like HDHomeRun or M3U playlists, with free guide data in the US, Canada, and UK. The server and core features are free; an optional Premiere key adds hardware-accelerated transcoding, DVR recording, offline sync, and Cinema Mode intros.

Manga, comics, ebooks, and light novels get a streaming-service-style home in Kavita - a fast, cross-platform reading server for the DRM-free collection you share with family and friends. It natively serves CBZ, CBR, CB7, ZIP/RAR/7z archives, raw images, EPUB, and PDF, with hand-crafted web readers per format: webtoon scrolling, single and dual-page spreads with advanced caching for the comic reader, and a book reader with adjustable fonts, spacing, margins, color themes, and column modes. Reading progress tracks per user, so everyone resumes exactly where they stopped on any device. Metadata parses from filenames, ComicInfo.xml, and EPUB fields, feeding index-backed search, smart filters, collections, reading lists with CBL import, and Want to Read queues. Role-based user management covers age restrictions, per-library access, and OIDC authentication. An OPDS feed connects third-party clients - Panels on iOS, Librera on Android, KOReader on e-ink devices - and a comprehensive REST API supports custom integrations. EPUB annotation and highlight support, custom theming, and full localization round it out. Built with .NET and Angular, it handles 50,000+ file libraries without strain; optional Kavita+ adds AniList scrobbling, recommendations, and external metadata.

Marketing campaigns and transactional mail from one open-source platform: Notifuse is a modern, self-hosted alternative to Mailchimp, Brevo, and Klaviyo without per-email or per-contact pricing. Built with Go and React on PostgreSQL, it separates concerns cleanly: a drag-and-drop visual builder composes responsive templates from MJML components with Liquid variables like {{ contact.first_name }} and per-template version history; campaigns add A/B testing across subject lines, content, and send times; and a REST transactional API serves application-triggered mail. Delivery routes through your choice of provider - Amazon SES, Mailgun, Postmark, SendGrid, SparkPost, Mailjet, or plain SMTP - with multi-provider failover. Contacts carry custom fields and a full activity timeline (messages, profile changes, webhook events), and real-time segmentation builds dynamic rules over properties, activity, and subscriptions. Event-driven automations create behavioral sequences, a notification center gives recipients self-service preference management, and an S3-compatible file manager handles images with CDN delivery. Multi-tenant workspaces with isolated databases and custom domains suit agencies. Open and click tracking report engagement in real time.

Carbon delivers a unified manufacturing operating system that eliminates the integration tax of running separate ERP, MES, and QMS platforms. The Remix and TypeScript frontend paired with Supabase PostgreSQL backend provides full-stack type safety from database schema to React components, with real-time subscriptions pushing production floor updates to every connected client. The built-in MCP server exposes 1,374 operations across 15 modules through three discovery tools, enabling AI agents to interact with manufacturing data while respecting attribute-based access control. Nested bill of materials with unlimited depth supports complex assemblies, while the MRP engine calculates material requirements across multi-level structures with configurable lead times and safety stock. The configurator handles configure-to-order scenarios with rule-based variant generation. Full lot and serial traceability from receiving through shipping satisfies AS9100, ISO 13485, CFR Part 11, and ITAR compliance requirements. Custom fields extend any entity without schema modification, and the app framework lets integrators build domain-specific modules that plug into the core navigation, permissions, and data layer. Typed API clients for TypeScript, Python, C#, and cURL enable programmatic access to every manufacturing operation. Docker-based local development boots Postgres, Redis, Inngest, and the application stack with a single CLI command. 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.

Monitoring and safeguarding Docker infrastructure without heavy enterprise software overhead is the primary mission of Statainer, an open-source management control center for container hosts. System operators inspect live CPU loads, memory consumption, network throughput, and disk I/O metrics across individual containers or comparative top-ranking charts. The interface groups containers by Compose projects, enabling administrators to start, stop, or restart entire application stacks and inspect real-time log streams without opening SSH sessions. The built-in Update Manager detects available image tags, executes single-click container updates, and maintains persistent deployment history with automated rollback capabilities for failed recreations. Custom alert configurations trigger instant notifications to Telegram, Discord, Slack, Pushover, or generic webhook endpoints whenever resource thresholds are breached or container health states change. Developers can provision scoped API keys with token authentication to automate container state transitions and export performance telemetry into custom monitoring workflows. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.