Open Source & Free Tools for Web Workers

happyconf.net is a web-based platform designed to transform inactive conference screens into professional, animated displays and provide organizers with practical event management tools.

The main features of this service include:

• Animated Slideshows: It allows organizers to create elegant presentations to highlight speakers, showcase sponsors, share announcements, and display quotes from the event.

• Integrated Event Utilities: Beyond slides, the platform includes a remote-controlled countdown timer, a large room clock, and a fair prize draw system to entertain and inform attendees during breaks.

• Web-Based and Installation-Free: The service runs entirely in a web browser, requiring no software installation; it can be projected onto any connected screen, TV, or projector.

• Professional Visual Themes: Users can choose from ready-made themes like "Cyberpunk," "Glassy," or "Romantic," or request a fully custom theme to match their specific graphic identity.

• Real-Time Dashboard: Content is managed through a private admin area, and the public display updates in real time as changes are made.

• Event-Based Pricing Model: Instead of a recurring subscription, it offers a "pay-per-event" system with tiers (Starter, Pro, and Custom) tailored to different event sizes, from small meetups to large professional conferences.

• Privacy and Data Sovereignty: To display content, a login is required; once an event is over, all user data is typically deleted to ensure privacy.

Sharry is a self-hosted web application designed and developed by eikek that allows users to share files conveniently.

The main features and capabilities of Sharry include:

• Account-Free File Sending: Send files to receivers without requiring them to register or sign up for an account.

• Peer File Receiving: Receive files from peers without requiring them to have an account.

• Resumable Uploads & Downloads: Features resumable uploads and downloads to ensure reliable file transfers even under unreliable network conditions.

• Open-Source & Documented: Maintained as an open-source project on GitHub with complete documentation.

Sumi.css is a minimalist, classless CSS framework designed to make plain, semantic HTML look clean and finished out of the box without requiring extensive utility classes.

The main features and capabilities of Sumi.css include:

• Ultra-Lightweight Footprint: Weighs only 6.7 KB gzipped with zero JavaScript and zero external dependencies.

• Automatic Light & Dark Mode: Automatically adapts to system light and dark color preferences out of the box, with support for forcing themes via data-theme="light" or dark.

• Classless Typography & Layout: Implements a fluid type scale that grows from a 1.2 ratio on mobile to 1.28 on desktop. Direct <header>, <main>, and <footer> children of <body> automatically center themselves.

• Semantic Component Styling: Provides built-in styles for semantic HTML elements including cards (<article>), accordions and dropdown menus (<details>), native modals (<dialog>), callout banners (.callout), buttons, forms, and striped tables (.striped).

• Grid & Flexbox Layout Helpers: Features an auto-fit layout grid (.grid), fixed column grids (.cols-2 through .cols-12 with .span-* modifiers), horizontal rows (.row), and vertical stacks (.stack).

• CSS Custom Property Customization: Driven entirely by CSS variables prefixed with --s-* (such as --s-primary, --s-bg, --s-surface, and --s-radius), making it simple to theme on :root or per component.

• Open Source: Distributed under the MIT License and inspired by frameworks like Basic.css, Pico.css, MVP.css, and Pure.

Seal is an open-source video and audio downloader for Android created by JunkFood02, functioning as a user-friendly graphical user interface (GUI) for yt-dlp. Written entirely in Kotlin and distributed under the GPL-3.0 license, it provides a modern experience for saving media across video platforms.

Key features and capabilities of Seal include:

• Universal Media Extraction: Downloads videos and audio files from any platform supported by yt-dlp.

• One-Click Playlist Downloads: Fetches entire video playlists at once with a single click.

• Metadata & Subtitle Embedding: Embeds subtitles into downloaded videos and uses mutagen to attach metadata and cover thumbnails to extracted audio files.

• Accelerated Downloads via aria2c: Utilizes embedded aria2c as an external downloader to process file downloads.

• Custom Command Templates: Executes custom yt-dlp command arguments using customizable templates managed directly within the app.

• Material Design 3 & Jetpack Compose UI: Built following Modern Android Development (MAD) guidelines in pure Kotlin with Jetpack Compose, a single-activity architecture, and Material Design 3 dynamic color themes.

• Open Distribution: Distributed as APK releases on GitHub (with arm64-v8a recommended) as well as on F-Droid.

Homarr is a simple, sleek, and powerful server dashboard that puts all your self-hosted apps and services at your fingertips in one convenient location.

The main features and capabilities of Homarr include:

• Drag-and-Drop Board Building: Build and arrange boards, apps, and widgets easily with a mouse or finger.

• 91+ Built-In Service Integrations: Connects directly with over 91 supported services—such as Plex, Jellyfin, Home Assistant, Pi-hole, qBittorrent, Sonarr, Radarr, Lidarr, and SABnzbd—to monitor status, activity, and controls directly on the dashboard.

• No YAML Configurations: Easily configure and manage boards, apps, widgets, and integrations directly through the visual interface without editing YAML files.

• Thousands of Built-in Icons: Includes access to repositories containing thousands of built-in icons for customizing your app links.

• Authentication & Access Control: Features built-in authentication supporting credentials, OIDC, or LDAP to precisely control what each user can see and manage.

• Multilingual Support: Supports 26 interface languages out of the box.

• LLM-Friendly Documentation: Provides standard documentation alongside LLM-readable Markdown versions (/llms.txt and /llms-full.txt).

Traggo is a self-hosted, tag-based time tracking tool. Designed to give users full control over their data without third-party access, it replaces rigid task structures with customizable, tagged time spans.

The main features and capabilities of Traggo include:

• Tag-Based Time Tracking: Eliminates fixed tasks in favor of flexible time spans categorized by customizable tags—such as project names or activity types like email, programming, and meeting.

• Customizable Dashboards: Provides visual analytics and statistics powered by customizable dashboards with diagrams.

• List & Calendar Views: Offers both list and calendar views to inspect and analyze tracked time over time.

• Self-Hosted Privacy: Requires self-hosting, ensuring total data ownership and security against third-party access.

• Web UI & User Management: Features a sleek web interface with multiple themes, easy setup, simple user management, and Semantic Versioning (SemVer) release tracking.

Tymeslot is an open-source meeting scheduling software licensed under the GNU AGPLv3 designed to eliminate back-and-forth emails by allowing clients to book appointments in real time.

The main features and capabilities of Tymeslot include:

• Multi-Calendar Synchronization: Connects to Google Calendar, Outlook / Microsoft 365, Microsoft Exchange, Apple iCloud, and other providers to check real-time availability and prevent double-bookings.

• Automated Video Meeting Links: Automatically generates meeting links when a booking occurs across providers such as Zoom, Google Meet, MiroTalk P2P, and Microsoft Teams.

• Elixir & LiveView Architecture: Built on Elixir's fault-tolerant runtime, Phoenix LiveView, and PostgreSQL, using circuit breakers to keep your booking page online even if third-party calendar or video APIs slow down.

• Customizable Themes & Branding: Offers customizable booking themes (such as Quill and Rhythm) with custom colors, fonts, background images, video backgrounds, and website embed options (inline, popup, or floating button).

• Privacy & Security Built-In: Operates without advertising pixels or third-party tracking using cookieless analytics, OAuth 2.0, AES-256 encryption for credentials, and account rate limiting.

• Flexible Hosting & Pricing: Fully free to self-host using Docker on your own server and custom domain, or available via a managed cloud service (€9/month Cloud Pro plan).

• Multilingual Interface: Provides browser auto-detection for dashboards and booking pages in English, German, French, Italian, Ukrainian, Czech, Polish, and Brazilian Portuguese.

Easy!Appointments is a free, open-source online appointment scheduling web application created by Alex Tselegidis that allows customers to book appointments directly via the web.

The main features and capabilities of Easy!Appointments include:

• Self-Hosted Web Infrastructure: Runs on a web server with Apache or Nginx, PHP, and MySQL, allowing easy installation in a single server folder alongside existing websites and shared databases.

• Google Calendar Synchronization: Syncs booking data seamlessly with Google Calendar, enabling users to manage schedules across external calendar services.

• CMS Extensions & Docker Integration: Provides official plugins for WordPress, Joomla, and Drupal, as well as an official Docker image for containerized server deployments.

• Customizable Industry Workflows: Designed with a flexible codebase adaptable to diverse scheduling environments—including healthcare, marketing, education, salons, recruitment, accommodation, restaurants, and event planning.

• SMS, Payments & Reminders: Supports extended operational tools, including SMS notifications, payment processing, performance reports, reminders, and third-party integrations.

• 100% Free & Commercial Licensing: Fully open-source and free to install with zero monthly fees or per-appointment commissions, even for commercial usage.

• Professional & Premium Services: Offers optional paid professional services for custom development, managed hosting, white labeling, data migration, installation support, and maintenance contracts.

CrawlerDetect is an open-source PHP library created by Mark Beech (JayBizzle) that serves as a standard for identifying crawlers, spiders, and bots from user-agent strings.

The main features and capabilities of CrawlerDetect include:

• Zero Network Overhead: Performs pure regular expression matching against a local signature database on your server, eliminating external API calls, latency penalties, or third-party network dependencies.

• Extensive & Updated Signature Database: Maintains a community-driven repository of thousands of known bot, spider, and crawler signatures—including modern AI agents—that is continuously updated.

• Streamlined Three-Method API: Features an intuitive, minimal surface area consisting of just three methods: isCrawler(), getMatches(), and setUserAgent().

• Zero-Configuration & Broad Ecosystem: Installs quickly via Composer without requiring setup or configuration files. It operates standalone, integrates natively with frameworks like Laravel, Symfony, and Yii, and offers community ports for Node.js, Python, Ruby, Go, .NET, and the JVM.

• Lightweight & Battle-Tested: Built as a single PHP class focused specifically on accurate bot detection, supported by over 114 million total downloads and active open-source maintenance.

Vela (or Vela Desktop) is an independent, open-source desktop environment for Linux designed as a modern, fluid, and sharp system for today's hardware. Built as a unified desktop rather than a collection of separate utilities, it combines its own Wayland compositor, Vulkan renderer, Qt Quick shell, file manager, and settings app. Released under the GPL-3.0-or-later license, Vela is currently in usable Alpha status.

Key features and capabilities of Vela include:

• Cohesive Modern Shell: Integrates a live acrylic blur background across panels, a Start menu with instant search and pinned apps, Task View with live window/desktop previews, a notification center, clipboard history, and a built-in snipping tool.

• Advanced Snap Layouts: Supports window snapping into halves, quarters, and six flyout arrangements (via drag, Super + arrow keys, or hovering the maximize button), creating snap groups that the taskbar manages and restores together.

• Custom Vulkan 1.4 Architecture: Built on wlroots for Wayland socket handling, but features its own custom scene graph and Vulkan 1.4 renderer with no OpenGL fallback or reliance on default wlr_scene renderers.

• Fluid, Monitor-Paced Rendering: Drives animations based on actual monitor vblanks (from 60 Hz up to 360 Hz) and renders frames as late as safely possible. If one application slows down, Vela prevents it from holding back the rest of the desktop or cursor.

• Pixel-Exact Fractional Scaling: Renders application buffers at exact physical pixel scales (such as 125% or 175%) without bilinear smearing, rounding window edges to physical pixels so snapped windows align without gaps or overlaps.

• Crash Resilience & Audio Engine: Uses a supervisor process to hold the Wayland socket if the compositor crashes—allowing applications to reconnect seamlessly—while keeping the lock screen secured via ext-session-lock. It also features native PipeWire and WirePlumber integration that plays audio at native sample rates.

• Lightweight Idle Footprint: Operates with an idle memory footprint of approximately 17 MiB PSS and 0.1% CPU usage.

CompatLab is an open-source tool designed to test and analyze npm package compatibility across major JavaScript runtimes, including Node.js, Bun, and Deno.

The main features and capabilities of CompatLab include:

• Multi-Runtime Load Testing: Tests published npm packages across Node.js, Bun, and Deno runtimes on Linux using exact runtime versions.

• Dual Consumer Mode Verification: Checks package loading through both import (ESM) and require (CommonJS) for root entry points as well as subpath imports and requires.

• Detailed Status Reporting: Categorizes loading outcomes into clear statuses (such as Passed or Inconclusive) and highlights subpath issues like missing optional peer dependencies.

• Disabled Install Scripts: Executes checks with install scripts disabled for safety during package testing.

• Open-Source Engine & CLI: Provides an open-source CLI engine (compatlab check) and public API so developers can reproduce scans locally on their own Linux hosts.

• MCP Integration for AI Agents: Offers a Model Context Protocol (MCP) server integration, allowing AI coding tools (such as Claude Code, Cursor, or Codex) to check compatibility reports directly.

Notifuse is a modern, self-hosted, open-source emailing platform designed as a cost-effective alternative to commercial services such as Mailchimp, Brevo, Mailjet, Klaviyo, and Listmonk.

The main features and capabilities of Notifuse include:

• Visual Email Builder & Liquid Templating: Features an intuitive drag-and-drop editor powered by MJML components for responsive layouts, real-time preview, and Liquid templating variables (such as {{ contact.first_name }}) for dynamic content.

• Transactional REST API: Provides a REST API to trigger transactional emails with responsive templates across modern devices.

• Automations & Behavior-Driven Workflows: Enables event-driven, multi-step journeys built on subscriber timelines with wait periods, conditions, and automatic sequence termination the moment a contact replies.

• Contact Profiles & Real-Time Segmentation: Tracks rich contact profiles with complete activity histories—including message interactions, web sessions, and page views—while supporting dynamic segmentation rules.

• A/B Testing & Cookieless Web Analytics: Offers built-in A/B testing for subject lines and content alongside a privacy-first, cookieless web analytics engine that tracks visitor engagement (TimeScore) and campaign conversions without consent banners.

• Multi-Tenant Workspaces & Permissions: Provides multi-tenant architecture with isolated data, custom domains per workspace, and granular role-based permissions.

• Integrated AI Assistant: Connects to AI providers (via Anthropic, OpenAI, or Gemini keys) and Firecrawl web research tools to generate subject lines, draft email blocks, or query analytics performance.

• Flexible Deployment & Pricing: Open-source and free to self-host, alongside paid self-hosted team licenses (from $290/year) and managed Notifuse Cloud plans (from $16/month).

Stirling PDF is a free, private, and open-source PDF editing and document processing platform designed to run on any infrastructure.

The main features and capabilities of Stirling PDF include:

• Privacy-First & Self-Hosted Architecture: Runs directly on your own machine or server, ensuring sensitive files remain secure and offline without landing on third-party websites.

• 60+ PDF Editing Tools: Provides a broad suite of tools for reading, editing, converting, merging, splitting, compressing, and validating PDF documents.

• AI Assistant for Natural Language Edits: Features an interactive assistant that performs in-place document modifications—such as redacting PII, translating, summarizing, and converting—using plain language commands.

• Automated Batch Pipelines: Enables creating automated processing pipelines to OCR scan, classify, redact, compress, and route thousands of PDFs at once to destinations like SharePoint.

• Programmatic APIs & MCP Support: Exposes every PDF operation via REST APIs and Model Context Protocol (MCP) to seamlessly integrate document processing into custom software and AI workflows.

• Policy Enforcement & Action Logging: Provides full audit logging and applies organizational rules automatically the moment a file arrives.

Komga is a media server designed for organizing and reading comics, mangas, BDs (bandes dessinées), magazines, and eBooks.

The main features and capabilities of Komga include:

• Multi-Format Library Organization: Organizes your digital library—including CBZ, CBR, PDF, and EPUB files—into libraries, collections, and reading lists.

• Flexible Reader Support: Allows reading directly through an integrated Webreader, the Mihon extension, any OPDS reader, or other client integrations.

• Metadata Management: Provides built-in tools to edit and manage metadata for both series and individual books.

• API & Ecosystem: Features a RESTful OpenAPI interface, multi-language translation support, and community resources on GitHub and Discord.

Rsync UI is an open-source web application created by Florian Dejonckheere that allows users to create, schedule, and automate file synchronization jobs using rsync through an intuitive web interface.

The main features and capabilities of Rsync UI include:

• Centralized Health Dashboard: Displays real-time job health, execution history, scheduled tasks, and storage usage.

• Local & Remote Synchronization: Manages file synchronization across local directories as well as remote SSH destinations with fully customizable rsync command-line arguments.

• Automated Scheduling & Real-Time Progress: Enables scheduled recurring jobs, real-time synchronization progress tracking, and custom pre- and post-synchronization execution hooks.

• SSH Management & Security Auditing: Simplifies remote server management through SSH key deployment, system resource monitoring, and SSH command auditing for security compliance.

• Customizable Notifications: Features built-in notification services to alert administrators of job statuses and completions.

• Containerized Architecture: Packaged as a Docker image running a Ruby-based application backend supported by a PostgreSQL database and intended to run behind a TLS-terminating reverse proxy (such as Caddy, Traefik, or Nginx).