When cybersecurity instructors and competition organizers host Capture The Flag tournaments, GZCTF orchestrates isolated per-team challenge containers, dynamic anti-cheat flags, and live exponential scoreboards from a single web platform. Event administrators can configure four distinct challenge modes covering static attachments, team-specific dynamic attachments, shared static containers, and isolated dynamic containers where unique flags are injected into each team's environment at launch. A customizable exponential scoring engine adjusts point values automatically as more teams solve a problem while awarding first, second, and third blood bonuses to top contenders. Built-in flag-sharing detection monitors every submission in real time, flagging suspicious cross-team flag reuse alongside live event streams and container logs. Participants can group into divisions, track their ranking trajectory on interactive score timelines, and upload post-game writeups directly into the portal for organizer review and batch archiving. Built-in network proxying forwards challenge traffic over WebSocket tunnels with optional packet capture so referees can audit exploit payloads during active matches. Multi-language localization, customizable branding, invitation gates, and email domain restrictions adapt the portal to university courses, corporate security drills, or international tournaments. 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.

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.

Organizers running sports leagues, gaming tournaments, and community athletics can deploy Bracket as an open-source competition control hub that coordinates multi-stage events without recurring SaaS subscription fees. Competition directors can configure multi-tier tournament topologies combining single elimination, double elimination, round-robin pools, and dynamic Swiss format brackets within a unified event schedule. An interactive calendar grid enables operators to drag and drop fixtures between designated courts, assign start times, and balance player recovery intervals across multiple playing areas. Public dashboard displays generate real-time match outcomes, court assignments, and standings boards that spectators can monitor on mobile devices or overhead venue monitors with customized team logos. Club administrators can manage multiple regional athletic organizations, register rosters through bulk CSV spreadsheet imports, and coordinate simultaneous divisions spanning amateur and championship flights. Integrated OpenAPI REST endpoints allow external scoring overlays, live stream graphic generators, and automated result bots to query match statuses or submit verified referee scorecards programmatically. 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.

Try an idea in React, Svelte, Python, or SQL without installing anything: LiveCodes is a browser-based playground where code compiles, runs, and previews the moment you type it. Starter templates open ready-made projects for most of the 90+ supported technologies. The desktop editor brings completion, multi-cursor editing, Emmet, and Vim or Emacs bindings, while a lighter touch-friendly editor takes over on phones and tablets. Packages from npm, deno.land/x, jsr, and GitHub import straight into your code, and a console, compiled-code viewer, and test runner show what happens behind the preview. Bring projects in from GitHub gists, GitLab snippets, JS Bin, or zip files, then share them as links or QR codes, export them as HTML, JSON, or zip archives, or send them to CodePen and JSFiddle. Deploy a project to a public URL on GitHub Pages, sync your work across devices, or broadcast your editor and result live to a classroom. An embed builder and SDKs for JavaScript, React, Vue, Svelte, Solid, Preact, and web components place playgrounds inside documentation pages, and prefilled code makes every example editable. Projects stay private by default. Local assets, snippets, themes, and dark or light modes tailor the workspace to each person. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Moodle gives teachers a place to build courses and learners a place to work through them, with quizzes, assignments, grading, and progress tracking on a learning platform you host yourself. Custom or weekly sections sit beside a course index, and Previous and Next buttons walk learners through activities in order. The activity chooser adds forums, wikis, glossaries, lessons, H5P content, and SCORM packages. Question banks can be shared across courses and track every edit, and quizzes combine calculated, ordering, and essay questions with due dates and Safe Exam Browser settings. Assignments offer in-browser PDF annotation, rubrics, and marking guides, and with a marking workflow several markers can leave separate feedback before grades are released. Peer assessment runs through workshops, competency frameworks feed learning plans, and Open Badges recognize achievement. With learning outcomes enabled, a course page lists each outcome beside the activities linked to it. Learners follow deadlines on a dashboard timeline, message classmates, and take course content offline in the official mobile app. Sign-in works through email self-registration, LDAP, Shibboleth, OAuth 2, or LTI, and enrollment through keys, cohorts, flat files, or PayPal. Administrators assign roles, build custom reports, and upload plugin ZIP files. AI actions can run on providers including OpenAI, Azure AI, Gemini, Ollama, and Anthropic Claude, and a course-level report shows how students use them. 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-or-later licensed.

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.

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.

SurveyKing combines survey creation and online examination in a single platform — generate complete questionnaires from plain English via built-in LLM integration, administer timed exams with anti-cheating proctoring, and collect structured data through 20+ question types including matrix questions, cascading selectors, file uploads, and electronic signatures. Built on Spring Boot 3 with a React and TypeScript frontend using the UMI framework and Ant Design components, version 1.12 delivers each question type with independent validation rules, data type controls, and formula calculations. The AI engine connects to mainstream LLMs for survey generation from natural language prompts and provides real-time answer explanations during practice sessions. Exam mode features item banks with Word and Excel bulk import, fixed and randomized question selection, composite paper assembly, live proctoring dashboards with anti-cheating controls, automatic and manual grading with per-question scoring, and PDF score report archiving. The visual logic designer and DSL expression engine handle show/hide conditions, required rules, skip branching, quota controls, randomization, and cross-tabulation analysis with SPSS export. Role-based access controls support multi-user collaboration with department and permission management via Spring Security and JWT authentication. Redis handles caching and queuing while MyBatis Plus manages database operations. Deploy via a single Docker command with embedded H2 for trials or Docker Compose with MySQL for production. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

By turning any browser into an interactive trivia controller and live scoreboard, Razzia gives event hosts, educators, and communities a self-hosted multiplayer quiz platform that replaces Kahoot. Players join in seconds with a six-digit room PIN or scannable QR code on their smartphones, while the host drives the shared screen from a password-protected manager console. Build quizzes directly inside the browser-based editor or import portable JSON files with single-choice, multiple-choice, numeric estimation, and ungraded survey questions. Attach images, audio clips, or video files up to 100 MB to any prompt, group questions into themed round categories, and display explanatory notes when correct answers are revealed. Scoring adapts to your rules: reward fast responses with time-weighted points, apply strict, balanced, or lenient multi-select grading, deduct penalties for wrong guesses, or switch to survey mode to gather live audience polls without a leaderboard. Hosts can lock rooms mid-game, enable automatic nickname generation, hide question prompts on player screens, and configure auto-advance timers between rounds. Drop a custom theme file and logos into the branding folder to white-label colors, fonts, and backgrounds, or connect physical ESP32 hardware buzzers over the documented WebSocket protocol. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Passive slide decks put audiences to sleep, which is why Claper turns any presentation into a two-way live session where every attendee can vote in polls, submit questions, and react in real time from their phone. Speakers upload existing PDF or PowerPoint decks directly into the web studio and interleave interactive poll, quiz, form, and web embed slides between their static pages without rebuilding presentations from scratch. Conference organizers and educators share a short join code or QR link so hundreds of participants can enter the attendee room instantly from any mobile browser without installing an app or creating an account. During the talk, the presenter console displays incoming audience questions sorted by upvote popularity, alongside moderation controls to approve, pin, hide, or mark inquiries as answered on the main screen. Live polling supports multiple-choice, rating scale, and open-text prompts that animate into real-time bar charts and percentage breakdowns as votes arrive, while timed quizzes grade participant responses automatically. Integrated real-time speech transcription generates live captions and searchable session transcripts so international and hearing-impaired attendees can follow every spoken word. Universities and corporate training teams connect Claper directly to Moodle or OpenID Connect identity providers via LTI 1.3 to synchronize student rosters, push quiz scores to gradebooks, and export complete CSV engagement reports after every session. 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.

From the call for abstracts to the badge handed over at the registration desk, Indico handles every step of running a conference, plus the weekly meetings and one-off lectures that fill the calendar around it. Events live in a nested tree of categories, and access rules can be set per category, event, session, or single contribution, with custom roles inside each event. Speakers submit abstracts, track reviewers score them against questions the organizers define, judges accept or reject them, and accepted talks become contributions that sit in a drag-and-drop timetable of color-coded sessions. Registration forms are assembled field by field, carry fees, and take payment through PayPal, Stripe, or SIX Payment plugins; attendees get QR-coded tickets, and a badge editor prints name tags for the whole room. A paper reviewing workflow collects full papers. Meeting pages keep minutes and slide decks attached to the talk they belong to. The room booking module adds approvals, recurring reservations, and audiovisual equipment, and the Zoom plugin creates online sessions straight from an event page. Calendar views span a month, week, or day, filter by category, and export to iCal for subscriptions. Scripts pull event data from the HTTP export API as JSON or XML with personal API tokens. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Used daily by millions of educators and learners in over 65 languages and embedded as the default virtual classroom in Moodle Cloud, Canvas, Sakai, D2L, Jenzabar, and Schoology — together comprising more than 75% of the worldwide learning management system market — BigBlueButton has been the leading open-source web conferencing platform for education since its creation at Carleton University in 2007. The platform delivers WebRTC-based real-time audio, video, and screen sharing with a tldraw v2-powered multi-user whiteboard featuring infinite canvas support, allowing multiple participants to annotate slides and draw simultaneously. Breakout rooms support up to eight concurrent groups with collaborative whiteboards enabled by default, and polling with customizable response types lets instructors assess understanding in real time. The built-in Learning Analytics Dashboard answers three questions at a glance: who is attending, who is participating, and who is learning based on poll responses, providing actionable engagement metrics without requiring webcam surveillance. Session recording captures audio, video, slides, chat, and whiteboard annotations for asynchronous playback on any device. The plugin architecture introduced in version 3.0 enables custom extensions, while IMS LTI 1.0 compliance allows integration with Blackboard, Desire2Learn, Pearson Learning Studio, and any conformant platform without custom code. The REST API enables programmatic session management, user authentication, and recording access for custom frontends like the included Greenlight application. Version 4.0 introduces LiveKit-based media and a redesigned interface. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. LGPL-3.0 licensed.