Keycloak is an open-source Identity and Access Management tool that adds authentication to applications and secures services with minimal effort. It eliminates the need for storing or authenticating users, providing user federation, robust authentication, user management, and fine-grained authorization. Keycloak offers a Single-Sign On feature, allowing users to authenticate with Keycloak rather than individual applications, ensuring a seamless login experience across multiple applications. It also supports social login and can authenticate users with existing OpenID Connect or SAML 2.0 Identity Providers. Keycloak has built-in support to connect to existing LDAP or Active Directory servers and provides a centralized admin console for managing all aspects of the server. It also offers an account management console for users to manage their own accounts. Based on standard protocols, Keycloak supports OpenID Connect, OAuth 2.0, and SAML, and provides fine-grained authorization services for advanced permission management.

KiCad is an open-source software suite for electronic design automation (EDA), enabling the design and simulation of electronic circuits and printed circuit boards (PCBs). It provides a comprehensive set of tools for schematic capture, PCB layout, and 3D visualization. KiCad supports extensive libraries of components and footprints, allowing designers to create custom designs with ease. Its robust features, such as design rule checking, netlist generation, and Gerber export, make it a preferred choice for professionals and hobbyists alike. With a focus on flexibility and open-source principles, KiCad empowers users to bring their electronic design projects to life.

KillBill is an open-source subscription billing and payment platform designed to simplify complex billing workflows for SaaS and other businesses. It provides robust support for recurring billing, invoicing, and payment management while offering flexibility for customization. KillBill ensures seamless integration with third-party payment gateways, making it adaptable for global payment needs. It supports multiple plugins to extend functionality, enabling businesses to manage tax compliance, analytics, notifications, and more. The platform's Kaui UI offers an intuitive administrative console for managing subscriptions, invoices, payments, and tenants. KillBill's API-driven design allows developers to customize and automate every aspect of the billing process. Its modular architecture ensures it can scale with the growing needs of businesses, providing robust tools for revenue management.

Kimai is an open-source time-tracking solution designed for freelancers, small businesses, and enterprises to manage time-tracking needs efficiently. It enables users to track work hours, manage projects, and create accurate reports and invoices based on time entries. With a focus on simplicity and flexibility, Kimai is ideal for organizations looking to improve productivity, manage employee timesheets, and handle client billing without the complexity of traditional ERP systems. Kimai offers a modular architecture, allowing for easy customization to meet unique requirements, and it supports multi-user environments with permissions to manage data access.

Komga is a free and open source comics/mangas server that provides an intuitive platform for comic and manga enthusiasts. It allows you to browse libraries, series, and books via a responsive web UI that is compatible with desktops, tablets, and phones. With Komga, you can easily organize your library with collections and read lists, and edit metadata for your series and books. The app also has the ability to import embedded metadata automatically. It features a web reader with multiple reading modes and allows you to manage multiple users with per-library access control, age restrictions, and labels restrictions. Additionally, Komga offers a REST API for interaction with other tools and scripts, and provides features for downloading book files, whole series, or read lists. It also has a duplicate files detection system and can import books from outside your libraries directly into your series folder. Komga also supports the import of ComicRack cbl read lists.

Kopia is a robust open-source backup and restore tool designed to provide fast and secure backups of your important data. It allows you to create encrypted snapshots of your files and directories, which can be stored on the cloud storage of your choice, network-attached storage, server, or locally on your machine. Kopia supports a wide range of storage locations including Amazon S3, Azure Blob Storage, Backblaze B2, Google Cloud Storage, and many more. It also supports both CLI and GUI versions, making it accessible for both advanced and regular users. Kopia's unique features include compression, deduplication, end-to-end 'zero knowledge' encryption, and error correction, ensuring your data is safe, secure, and easily retrievable.

Kutt is a free and open-source app designed to make your links shorter and more manageable. With Kutt, you can create, protect, and delete your links, and monitor them with detailed statistics. You can also set custom domains for your links, adding a personal touch to your URLs. The app also provides an API, allowing you to create, delete, and get URLs from anywhere. Kutt also offers browser extensions for Chrome and Firefox for easy access and use. The app is completely open source and free, giving you the freedom to host it on your own server if you wish.

Kuzzle is a free and open-source backend platform designed to accelerate the development of web, mobile, and Internet of Things (IoT) applications. It provides real-time features, multi-protocol API support, and robust user management, enabling developers to focus on building high-level business functionalities. Kuzzle is fully customizable through plugins and offers client SDKs for seamless integration with various platforms. Its flexibility and scalability make it an ideal choice for IoT, geolocation, and enterprise applications.

Label Studio is an open source data labeling tool. It lets you label data types like audio, text, images, videos, and time series with a simple and straightforward UI and export to various model formats. It can be used to prepare raw data or improve existing training data to get more accurate ML models.

Langflow is an innovative application designed to facilitate the experimentation and prototyping of LangChain pipelines. It provides a user-friendly interface for creating flows by simply dragging and connecting LangChain components such as LLMs, prompt serializers, agents, and chains. You can easily modify prompt parameters, link chains and agents, track an agent's thought process, and export your flow. Once your flow is ready, you can export it as a JSON file for use with LangChain. Langflow also integrates with langchain-serve for one-command deployment to Jina AI Cloud. With Langflow, building and deploying LangChain pipelines has never been easier.

Langfuse is a powerful, self-hosted observability platform designed for AI applications. It simplifies monitoring, debugging, and optimizing your AI workflows with detailed insights, customizable metrics, and flexible integrations. Langfuse provides a clean and intuitive interface, robust API access, and plugin support to extend its functionality. It ensures privacy and compliance by allowing you to maintain full control over your data with a self-hosted solution. The application is accessible via your host and supports multi-platform awareness, ensuring compatibility with various architectures.

LanguageTool is your personal writing assistant, designed to enhance your writing skills and ensure error-free communication. This multilingual app offers a comprehensive spelling, style, and grammar checker, capable of correcting or paraphrasing texts in a variety of languages. It integrates seamlessly with various platforms including browsers like Chrome, Edge, Firefox, Safari, Opera, and email platforms like Gmail and Outlook. It also works with office plugins such as Google Docs, Word, OpenOffice, and LibreOffice. LanguageTool is equipped with an AI-based style and grammar checker trusted by renowned organizations worldwide. It offers a distraction-free writing experience, a personal dictionary, and quality scoring for evaluating style and grammar. The app also features a 'Picky Mode' for advanced punctuation, style, and typography suggestions. LanguageTool is not just about correcting mistakes, it also helps improve your writing style by detecting overused phrases, foreign terms, redundant words, and improper word choice. It even assists in paraphrasing sentences to make them more formal, fluent, simple or concise. LanguageTool is the perfect tool for anyone who wants to deliver clear, precise, and stylistically correct writing.

Lavalink is a standalone audio sending node designed to facilitate the process of sending audio without it ever reaching any of your shards. It is powered by Lavaplayer and Koe, and is currently being used in production by several popular bots. The app offers a range of features including Twitch/YouTube stream support, an event system, seeking, volume control, and a REST API for resolving Lavaplayer tracks and controlling players. It also provides statistics which are useful for load balancing. Lavalink is designed to have a minimal CPU/memory footprint, and it supports plugins. It is compatible with Java 17 LTS or newer, and it follows Semantic Versioning.

LazyLibrarian is an open-source tool designed to manage and automate the downloading, organizing, and serving of eBooks, audiobooks, and magazines. It integrates seamlessly with Usenet and torrent services to fetch content based on user preferences. With LazyLibrarian, you can search, download, and manage your media library effortlessly. It supports multiple download providers, metadata retrieval, and integration with Calibre for organizing your eBook collection. LazyLibrarian is user-friendly, flexible, and provides a centralized solution for book lovers to manage their digital libraries.

Leantime is an open-source project management system designed for startups and small teams. It offers a simple and intuitive interface to manage tasks, projects, and team collaboration efficiently. With Leantime, you can organize your work using timelines, kanban boards, and task lists. It also includes features like time tracking, milestones, and idea boards to streamline project workflows. Leantime supports integrations with various third-party tools, making it a flexible and scalable solution. Its emphasis on usability and simplicity ensures that teams can focus on productivity and achieving goals. Leantime is distributed under an open-source license, allowing for customization to meet the unique needs of any organization.

Lenpaste is a web service that allows you to share notes anonymously. It is an open-source alternative to pastebin.com. The app supports multiple languages and uses cookies only to store settings. It can work without JavaScript and has its own API. Lenpaste allows you to set maximum length for the paste title and body, maximum lifetime of the paste, and rate limits for viewing and creating pastes. It also provides options to prohibit search engine crawlers from indexing the site and to set information about the server admin. Lenpaste is self-hosted and provides a list of public servers managed by various contributors.

LibreOffice is a free and powerful office suite app that serves as a successor to OpenOffice.org. It features a clean interface and feature-rich tools that help you unleash your creativity and enhance your productivity. The app can be accessed at http://yourhost:3000/ or https://yourhost:3001/. It is designed to deliver a true lossless image at a high framerate to your web browser. The app also supports multiple architectures, ensuring that it can be used on a variety of platforms. This app is perfect for those who need a comprehensive office suite for their daily tasks.

LibreTranslate is a free and open-source machine translation app that is entirely self-hosted. Unlike other translation apps, it does not rely on proprietary providers such as Google or Azure to perform translations. Instead, its translation engine is powered by the open-source Argos Translate library. LibreTranslate can translate text between different languages, auto-detect the language of the input text, and even handle HTML content. It provides a simple and intuitive interface for users to input the text they want to translate, select the source and target languages, and get the translated text. With LibreTranslate, you can enjoy a reliable, accurate, and privacy-friendly translation service right at your fingertips.

Lidarr is an audio collection manager designed for Usenet and BitTorrent users. It monitors multiple RSS feeds for new music and interfaces with clients and indexers to grab, sort, and rename albums and songs. Lidarr also has the capability to automatically upgrade the quality of existing tracks in your library when a better quality format becomes available. The app features a calendar to see all your upcoming releases in one place, manual search to find all the releases and choose the ones you want, and automatic handling of failed downloads. Lidarr ensures you get the right release every time with its custom formats feature, which allows fine control over release prioritization and selection. It also supports major platforms like Windows, Linux, macOS, and others.

LightDash is a modern, open-source business intelligence (BI) and data exploration tool designed to help teams visualize and understand their data. It connects directly to your existing data warehouse and provides an intuitive interface for building and sharing dashboards. With LightDash, you can create actionable insights from your data without needing advanced technical skills.

Welcome to LimeSurvey, the world's #1 survey platform designed to provide you with the best online survey tool that's fresh, quick, and anonymous. Whether you're a student, professional, or enterprise, LimeSurvey allows you to design a survey and gather insightful data, all for free. With LimeSurvey, you can create a simple questionnaire or poll, or even a sophisticated survey with complex validation rules, conditional logic, and quota management. It's the perfect alternative to Google Forms or Doodle. LimeSurvey is also the optimal online survey tool for research institutes, universities, and other educational establishments, offering free surveys, polls, and other open-source possibilities. With easy-to-use templates and an on-hand customer service team, LimeSurvey is your go-to solution for all your survey needs.

Linkding is a self-hosted bookmark manager that allows you to efficiently manage and organize your bookmarks. With a clean and optimized user interface, you can easily add, share, and edit bookmarks. The app also allows you to add notes to your bookmarks using Markdown and provides a 'read it later' functionality. It automatically generates titles, descriptions, and icons for your bookmarked websites and creates snapshots of them on the Internet Archive Wayback Machine. You can also import and export bookmarks in Netscape HTML format. The app offers light and dark themes for your convenience. It also provides a REST API for developing third-party apps and an admin panel for user self-service and raw data access.

LinkStack is a powerful open-source alternative to Linktree, designed to provide an efficient solution for managing and sharing links online. It offers a highly customizable link sharing platform with an intuitive, user-friendly interface. Unlike other link management platforms, LinkStack allows users to host their links on their own web server or web hosting provider, giving them complete control over their online presence. This makes LinkStack an ideal solution for businesses and organizations looking to manage multiple links. With LinkStack, users can easily link to their own custom page and provide their followers with access to all the links they need in one convenient location. LinkStack also offers a self-hosted option for users who want complete control over their data without having it sold to third-party companies. The platform can be easily implemented through a simple drag and drop process, eliminating the need for complex terminal commands or source code manipulation. LinkStack is committed to providing a free, privacy-focused solution for managing and sharing links online, without sacrificing user privacy and control over their data.

LinkWarden is a powerful, self-hosted service designed for managing and archiving bookmarks. It provides an intuitive interface for organizing and accessing your saved links, supports advanced features for enhanced productivity, and offers detailed link preservation options. With LinkWarden, you can maintain control over your bookmarks and ensure they remain accessible.

Listmonk is a self-hosted, high-performance mailing list and newsletter manager. It is designed to manage millions of subscribers across various single and double opt-in lists, with custom JSON attributes for each subscriber. The app allows you to query and segment subscribers with SQL expressions and offers a fast bulk importer for easy integration with external CRMs and subscriber databases. Listmonk also provides a simple API for sending transactional messages to subscribers using pre-defined templates. These messages can be sent via email, SMS, Whatsapp, or any medium via Messenger interfaces. The app also includes simple analytics and visualization tools, a powerful templating system for creating dynamic email templates, and a media manager for uploading images for email campaigns. Listmonk is free, open-source, and designed for high performance, with a single binary application that runs everywhere with a minimal CPU and memory footprint.

LiteLLM is a lightweight, self-hosted library designed for integrating language models like GPT into your applications. It provides an easy-to-use interface for sending and receiving prompts and responses, with support for multiple model configurations, API keys, and detailed debugging options. With LiteLLM, you can streamline your AI workflows while maintaining full control over your data and configurations.

Llana is a lightweight no-code API wrapper that exposes a REST API for any database within minutes. Stop wasting time building endpoints, just connect your database and start playing. Open source, free to use, and no vendor lock-in.

LobeChat is an open-source, AI-powered chat application designed to integrate with OpenAI services. It provides a seamless user experience, combining conversational AI capabilities with a customizable and extensible architecture. LobeChat is ideal for both personal and professional use cases, offering robust features for modern AI chat applications.

Logseq is a powerful tool designed to enhance your note-taking and task management experience. It allows you to connect your notes, increasing your understanding and productivity. With features like PDF Annotations, Flashcards, and Whiteboards, it caters to a wide range of users including students, academics, writers, project managers, and developers. Logseq helps you capture, structure, and review your class notes with ease using the Linked References, Queries, and Search features. It also aids in memorizing facts and insights using the Flashcards feature. You can organize your thoughts and ideas, and quickly turn them into outlines using Block References. The app also offers tips and tricks to improve your note-taking skills, whether you're a beginner, intermediate, or expert. With Logseq, you can create your own processes, generate tables of relevant information, and always find what you're looking for. It also helps you stay on top of your relationships, conversations, and meetings, making it a safe space for your thoughts. Logseq is designed to store your interests, questions, ideas, favorite quotes, reminders, reading and meeting notes easily and future-proof. It also offers real-time, encrypted file syncing so you'll always have your notes backed up and securely available on any device. The Whiteboards feature provides a new canvas for your thoughts, allowing you to connect, associate and understand in new ways.

Logto is an Auth0 alternative designed for modern apps and SaaS products. It offers a seamless developer experience and is well-suited for individuals and growing companies.