End-to-end encrypted by design, CryptPad is a real-time office suite where teams write documents, plan on kanban boards, collect answers with forms, and draw diagrams without the hosting server ever seeing their content. Rich text pages come with comments, replies, @mentions, and a document outline, while the Markdown editor adds a live preview, Mermaid diagrams, mind maps, and math. Kanban columns hold colored, tagged cards with Markdown bodies, and the diagram editor exports PNG, JPG, SVG, or PDF. Optional ONLYOFFICE editors add spreadsheets, word-processing documents, and presentations that several people can edit together. The form builder offers text, choice, grid, date, ranking, and poll questions, conditional sections, and separate author, auditor, and participant roles. Documents can be shared with contacts or teams, by link, or as embed code, with view, edit, present, or view-once access. Passwords, expiry dates, owner lists, and access lists limit who gets in, and every edit lands in a history you can step through, restore, or pin as a named snapshot. CryptDrive keeps files in folders, tags, templates, and a trash bin, while teams get their own drive, chat, and member roles. 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.

Typeform's conversational format, self-hosted: HeyForm is the open-source form builder that presents one question at a time. Forms present one question at a time, which measurably improves completion rates compared to long static pages. It supports 40+ field types, from text, email, and phone inputs to picture choices, date pickers, star ratings, signatures, and file uploads. Conditional logic shows or hides questions based on earlier answers, routes respondents to different endings, and redirects to URLs, so a single form can serve multiple flows. Completed submissions land in a results dashboard with drop-off and completion analytics, and connect outward through webhooks or integrations with Zapier, Make, Google Sheets, Notion, Airtable, and Slack. Theming covers fonts, colors, backgrounds, and custom CSS, so embedded forms look native to your site rather than like a third-party widget; the JavaScript embed library renders them inline, as popups, or full-page, with shareable standalone links as the default. Team workspaces and projects with member management let multiple teams share one instance without mixing data. Self-hosting removes per-response pricing entirely - unlimited forms and submissions for flat hosting cost - and keeps lead data, feedback, and quiz answers in your own MongoDB, simplifying GDPR compliance. The stack is a NestJS server and React webapp backed by MongoDB and KeyDB, distributed under GPLv3 as a Docker image.

With 3,500+ GitHub stars and 100+ pre-built templates, OpnForm delivers a drag-and-drop form builder that handles everything from simple contact forms to multi-page surveys with conditional branching, calculations, and payment collection. The Laravel 11 API paired with a Nuxt 3 Vue frontend provides a responsive no-code editor supporting 20+ field types including text, date, file upload, signature capture, star ratings, phone numbers with country codes, and rich text. Conditional logic enables dynamic show/hide rules, required-field toggling, and calculated values that react to user input in real time. Submissions flow through configurable integrations — Slack notifications, Discord webhooks, Zapier connections to 5,000+ apps, Google Sheets sync, and custom webhook endpoints with full payload control. AI-powered form generation lets users describe a form in plain language and receive a ready-to-publish result. OIDC single sign-on with configurable state enforcement secures multi-user workspaces, while form-level passwords and CAPTCHA protection guard public-facing pages. Analytics dashboards track submission rates, completion times, and drop-off points. Forms embed via iframe on any website, Notion page, or custom domain with removable branding and custom CSS/JavaScript injection. The Docker Compose stack bundles the API, queue worker, scheduler, Nuxt client, PostgreSQL 16, Redis 7, and Nginx ingress proxy for a single-command deployment. 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.

In-app, website, link, and email surveys feed one open-source experience management platform: Formbricks. Its distinguishing strength is targeted in-app research: a JavaScript SDK triggers surveys on user events and attributes, with segmentation rules like "power users who have not seen a survey in 10 days," so questions reach the right cohort at the right moment instead of a mass email blast. The no-code editor offers 20+ question types including NPS, CSAT, CES, matrix, ranking, and file upload, with skip logic, conditional branching, best-practice templates, and full brand theming. Responses feed built-in analytics with summaries and CSV/JSON export, and integrations push data to Slack, Notion, Google Sheets, Airtable, Zapier, and n8n, with webhooks and an open API on every tier. Because self-hosted surveys load from your own domain rather than a blacklisted third-party script host, ad blockers do not suppress them - in-app surveys reach users that Hotjar-style tools silently miss, which measurably raises response rates. Self-hosting also removes the third-party sub-processor from your privacy policy entirely: survey responses often contain PII, and keeping them on your own server matters for GDPR-sensitive and regulated industries. The Community Edition has no response caps or tier-gated features, so core functionality and your data stay accessible regardless of any subscription. Next.js on PostgreSQL, AGPLv3.

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.

The drawing surface inside WebRTC conference tools like Meetzi and the LAMS online-learning platform is Whiteboard (by cracker0dks) - a lightweight Node.js collaborative sketchboard built to be embedded and customized, which also slots into Nextcloud via the External Sites app. Everyone opening the same whiteboardid URL parameter draws on the same board, with remote user cursors visible live, per-user undo/redo, and an indicator showing the smallest participating screen so nobody draws outside a colleague's view. Content handling goes beyond pen strokes: drag-and-drop or paste images and PDFs from any PC or browser, then resize, rotate, and draw over them on canvas or background; add text and sticky notes; hold Shift for angle-snapped lines and perfect squares. Every function has a keybinding - deliberately friendly to pen displays like Wacom and XP-Pen whose hardware buttons map to shortcuts. Boards save to image or JSON (with reload), export directly to Nextcloud via WebDAV, and persist across restarts with the file-database option. A REST API with bundled interactive docs allows full programmatic control, an optional access token locks down uploads, and YAML configuration tunes behavior and performance. MIT-licensed and reverse-proxy friendly.

A Node.js server, a large shared canvas, and a URL - WBO (Whiteboard Ophir) is collaborative whiteboarding reduced to its essence. There are no accounts and no setup - to collaborate, you send someone the board's link, and every stroke appears for all connected users in real time over WebSockets, with cursor positions shared so you can see where collaborators are working. Board state persists automatically and continuously, so a diagram drawn in today's lesson is still there next week at the same URL. Boards come in three flavors: a public free-for-all, private boards with random unguessable names, and named boards with custom URLs shared by anyone who knows the name. The tools cover teaching and brainstorming needs - pencil, straight lines, rectangles, ellipses, text annotations, eraser, a full color palette with brush sizes - and boards export as SVG or PNG. Despite the simplicity, the server is production-minded: JWT authentication gates board access with granular capabilities (open, edit, and clear as separate permissions), rate limiting caps per-client message volume, reverse-proxy and subpath deployment are supported, and OpenTelemetry provides metrics, logs, and traces. It works on tablets and touch devices, speaks multiple languages, and consumes minimal resources. AGPL-licensed.

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.

In continuous open-source development since 2009, Etherpad is the original really-real-time collaborative editor - used by Wikimedia, governments, EU public-sector institutions, and tens of thousands of self-hosters. Its core idea is visible authorship: every keystroke is attributed with author colors, every revision preserved, and the timeslider lets you scrub through a document's entire history character by character. Multiple people type into the same pad and see each other's changes instantly - it scales to thousands of simultaneous editors per pad. The base install is deliberately lightweight; capability comes from roughly 290 plugins installable from the admin web UI: comments, images, tables, drawing, video chat via WebRTC, math rendering, code highlighting, and authentication via OAuth, LDAP, or OpenID. AI is pointedly a plugin, not a default - you choose the model and infrastructure, or never turn it on. There is no telemetry. For integrators, an HTTP API (with OpenAPI definitions at /api/openapi.json) manages pads, users, and groups for embedding in your own applications, and the ueberDB abstraction layer supports PostgreSQL, MySQL, Redis, MongoDB, and SQLite backends. Full data export is built in, the format is open, it is translated into 105 languages, and it runs on anything from a Raspberry Pi to a server farm. Apache 2.0 licensed, Node.js based.

Pretix powers thousands of events and millions of ticket sales through a fully brandable ticket shop with interactive seating plans, 30+ payment providers, and a mobile check-in app for venue entry management. With over 2,400 GitHub stars, it delivers what organizations need when they demand full control over attendee data and revenue rather than surrendering margins to Eventbrite or Ticket Tailor. Built with Python and Django on PostgreSQL with Redis and Celery, the ticket shop adapts to your colors, logo, and domain with responsive design. The graphical seating plan editor handles everything from small cinemas to large stadiums, letting buyers choose seats mapped to pricing categories. Payment providers connect through plugins including Stripe, PayPal, Mollie for iDEAL and Bancontact, SEPA direct debit, and bank transfer with automatic CSV import for payment matching. The voucher engine generates bulk discount codes with usage limits, quota reservations, and automated email distribution. Waiting lists automatically offer released tickets to the next registrant with expiration deadlines. A built-in mini-CMS hosts event descriptions, terms of service, and static pages directly in the ticket shop. Customer accounts enable repeat buyers to check out faster across events. The pretixSCAN mobile app performs QR code check-in on Android and iOS with offline capability. Embeddable JavaScript widgets integrate the shop into any website. Plugin architecture extends functionality with output formats, analytics, and Apple Wallet passes. Deploy via Docker with the pretix/standalone image alongside 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. AGPL-3.0 licensed.

Alf.io handles the complete conference and event lifecycle from ticket distribution through check-in to financial reporting, built for organizers who refuse to surrender attendee data to third-party ticketing platforms like Eventbrite or Tito. Built on Java 17 with Spring Boot and PostgreSQL with row-level security policies, the project has earned over 1,500 GitHub stars from privacy-conscious event organizers across Europe and beyond. Payment processing supports Stripe for credit cards, Mollie for iDEAL, Bancontact, KBC/CBC, and Przelewy24, plus Revolut, PayPal, bank transfers, on-site collection, and configurable custom offline payment methods with localized instructions. Multi-tier ticket categories enable early bird, VIP, standard, and free registrations with promotional codes, group discounts, and waiting lists that automatically notify next-in-queue when cancellations occur. Customizable registration forms collect attendee data beyond standard fields, while EU VAT management validates tax IDs through the VIES web service and supports Italian e-invoicing with automatic PDF invoice generation attached to confirmation emails. The Alf.io Scan mobile app for iOS and Android performs QR code check-in at venue entrances, and the Alf.io-PI project provides Raspberry Pi-powered offline-capable check-in stations that form encrypted clusters for high-throughput badge printing at large events. Apple Wallet integration delivers digital passes via PassKit. The extensions system integrates with CRMs, accounting platforms, Slack, Telegram, and Mailjet. Multi-language support covers nine languages. Deploy via Docker with PostgreSQL. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. GPLv3 licensed.

Hi.Events is an alternative to Eventbrite, Tickettailor, and Dice.fm, eliminating per-ticket platform fees entirely when self-hosted. Event organizers create fully brandable event pages supporting paid, free, donation, and tiered ticket types with recurring and multi-date scheduling, sold-out waitlists that automatically release tickets when spots open, and product add-ons with category organization. Stripe Connect integration processes payments directly to the organizer's bank account with instant payouts, while offline payment methods support cash and invoice scenarios. Promo codes offer fixed or percentage discounts with usage limits, expiry dates, and promo-gated hidden tickets for VIP access. QR code check-in enables fast door scanning with multiple check-in lists, scan logs, and real-time attendance tracking across entry points. Custom checkout questions collect attendee information beyond standard fields, with advanced search, filtering, CSV and XLSX export, full and partial refunds, and bulk attendee messaging. The analytics dashboard tracks daily sales, revenue, tax breakdowns, product performance, and promo code usage with exportable reports, while affiliate tracking assigns custom codes to promoters with tracked sales data. Multi-user roles control organizer permissions, automatic invoicing generates receipts, and the REST API ships with interactive OpenAPI documentation. 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.

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.

LearnHouse delivers a modern open-source learning platform that replaces proprietary course builders with a self-hosted alternative shipping a rich feature set out of the box. The Tiptap-powered block editor supports videos, documents, embeds, quizzes, and file uploads in a Notion-like interface with real-time co-editing powered by Hocuspocus and Yjs CRDT synchronization over WebSocket. AI tutoring integrates Google Gemini and LlamaIndex for RAG-powered context-aware assistance that adapts to course content, while interactive Playgrounds use AI to generate simulations, diagrams, and learning exercises. The platform handles the full course lifecycle: chapters and activities organize into collections and learning paths, assignments support automated and manual grading, and code blocks execute student submissions in 30+ languages with auto-grading. Analytics dashboards track learner engagement, progress, and completion rates in real time. The backend runs on FastAPI with SQLModel and Alembic migrations against PostgreSQL 16 with pgvector for AI embeddings, while Redis handles caching and session management. The frontend builds on Next.js 16 with React 19 and Tailwind CSS v4. Deployment uses an interactive CLI wizard that configures domain, database, admin account, SSL via Let's Encrypt, and optional features like email via Resend, S3 storage, and Google OAuth, then generates a Docker Compose stack ready to start. On RepoCloud, deploy LearnHouse on a dedicated VPS with root SSH access, persistent PostgreSQL storage for your course data, and complete control over AI provider keys and branding customization, all under the AGPL v3 license.