Open-source alternatives to Flowchart Fun

Penrose is a compiler that transforms structured mathematical notation into optimized SVG diagrams. It uses a three-stage pipeline of separate domain, substance, and style files to define mathematical objects, relationships, and visual presentation, then solves continuous optimization problems with user-defined spatial constraints and objectives to automatically arrange diagram elements. The system separates diagram content from visual style using distinct declarative languages, and provides a typed domain language with subtype hierarchies for mathematical objects. It supports embedding compi

This project is an AI-powered diagramming tool that converts natural language descriptions into editable visual charts and hand-drawn style sketches. It integrates large language models to translate text-based concepts into structured visual maps and coordinate data for a drawing canvas. The system features a dedicated provider manager for the secure configuration of API keys and credentials for external language models. It employs a visual flow optimizer that calculates optimal connection points for arrows and dynamic layout positioning to reduce overlap in complex diagrams. The tool combin

Flowchart.js is a JavaScript library that converts a simple text-based domain-specific language into SVG flowcharts. It parses DSL keywords to define node types such as start, end, operation, condition, parallel, and subroutine, then renders them as distinct SVG shapes connected by directional paths. The library distinguishes itself through its styling and interactivity capabilities. It supports applying CSS classes to SVG elements for external stylesheet overrides, as well as inline attribute overrides for per-node and per-edge visual properties like fill, stroke, and font. Flowchart.js also

This project is a renderer and theme engine for Mermaid.js that converts diagram syntax into styled SVG graphics and ASCII text. It provides a type-safe diagram editor and a pipeline for transforming diagram source code into scalable vector graphics or plain text visuals. The system features a dedicated theme engine that maps editor colors and CSS variables to diagram elements. It enables dynamic diagram theming through CSS custom properties for real-time color updates and supports index-based styling to override the appearance of specific nodes and edges. The tool covers a range of visualiz

Vditor is a browser-based Markdown editor and rendering engine that supports multiple editing interfaces, including a visual rich-text experience, instant rendering, and a traditional side-by-side split-view preview. It serves as an authoring tool for technical documentation and a component for web-based editor integration. The project is distinguished by its support for complex technical content, utilizing specialized rendering for mathematical formulas, flowcharts, sequence diagrams, and mind maps. It also functions as a collaborative document review tool, enabling users to attach anchored

Util is a comprehensive development framework for .NET designed to implement layered architectures and domain driven design. It provides a toolkit of base classes and tools for building full stack applications, specifically focusing on the creation of backend admin frameworks and management interfaces. The project distinguishes itself through a boilerplate generator that produces the necessary types and classes to standardize repetitive architectural patterns. It also includes a micro-frontend orchestrator that enables the splitting of large frontend modules into independent projects for sepa

Pluto.jl is a reactive computing environment for Julia that functions as a programmable document format. It serves as an interactive data science IDE and a polyglot computational notebook that stores Julia code and environment dependencies as versionable source files. The system is distinguished by its reactive execution model, which uses a directed acyclic graph to track variable dependencies and automatically re-evaluate affected downstream cells when a value changes. It ensures reproducibility by integrating isolated package environments directly within the notebook file and persisting con

nofwl is a cross-platform desktop client for interacting with large language models. It serves as a graphical user interface that connects to external artificial intelligence services using personal API keys. The application provides a localized experience with support for multiple system languages and customizable visual themes, including light, dark, and system-synchronized schemes. It operates across Windows, macOS, and Linux. The client manages conversation history and user configuration through local-first data storage, persisting chat messages as structured text files on the user's dev

Aureuserp is a modular open-source enterprise resource planning system and business suite designed to integrate accounting, inventory, manufacturing, human resources, and project coordination into a single centralized database. It functions as a comprehensive platform for managing business operations, sales orders, and procurement. The system uses a modular architecture that allows for the installation or removal of specific feature modules to tailor application capabilities to business needs. It includes a localization layer to translate the user interface into multiple languages and employs

Apollo Universal Starter Kit is a full-stack application boilerplate and starter template designed to accelerate cross-platform development across web, mobile, and server environments. It provides a modular architecture that organizes code into independent, self-contained feature directories, combined with a GraphQL-driven data layer and a server-side rendering pipeline to optimize performance and search engine optimization. The project incorporates compile-time code generation tooling to automatically scaffold schemas, resolvers, and components, alongside a real-time subscription engine for

Akaunting is a modular business enterprise resource planning system and self-hosted accounting software. It provides a comprehensive platform for small business financial management, centering on a double-entry bookkeeping system with a general ledger and chart of accounts. The platform is designed for extensibility through a module-based architecture and a dedicated marketplace for procuring third-party applications. It supports multi-tenant data isolation and utilizes role-based access control to manage granular user permissions. Its capability surface covers a wide range of business opera

Rallly is a group scheduling tool and collaborative event planner designed to coordinate meeting dates and collect participant availability. It functions as a multi-tenant meeting coordinator that allows users to propose date options via polls, visualize overlapping free time in a grid, and finalize meeting arrangements across different time zones. The project is built as a self-hosted scheduling application that can be deployed on private infrastructure using a containerized stack. This deployment model enables full data ownership and includes capabilities for corporate identity branding, al

js-sequence-diagrams is a JavaScript library used to generate SVG sequence diagrams from plain text descriptions. It functions as a text-to-diagram tool that transforms structured textual input into scalable vector graphics to represent system interaction flows. The library provides capabilities for system workflow visualization and technical documentation automation. It maps the communication between different components or services by converting text into visual representations of logic flows. The tool includes support for custom typeface loading to change the visual style and lettering of

This project is a collection of standardized markdown layouts and component libraries used to organize project documentation, user profiles, and technical diagrams. It provides predefined templates for creating professional GitHub profile pages and structured documentation for open source projects, including guides for installation, usage, and contribution. The library features specialized templates for rendering flowcharts and sequence diagrams using text-to-visual syntax. It also includes a system for integrating dynamic profile statistics and status cards that automatically display user co

go-diagrams is a Go visualization library and DOT language generator used to create system architecture diagrams. It implements a diagrams-as-code approach, allowing users to define system components, infrastructure dependencies, and data flows using Go source code. The library translates these code-based definitions into Graphviz DOT syntax, which is then processed by the Graphviz toolset to render final visual image assets. It supports mapping directional edges to illustrate dependencies and organizing related components into named clusters or subgraphs to represent architectural boundaries

Beautiful React Diagrams is a component library for building interactive node-based visualizations and flowcharts within React applications. It provides a framework for rendering custom visual schemas where nodes and links are managed through a centralized state, ensuring a single source of truth for complex layouts. The library distinguishes itself through a flexible rendering pattern that allows for the injection of custom user-defined components into node and port placeholders. It enforces structural integrity by validating connections against predefined schemas and provides granular contr

svgbob is an ASCII to SVG converter and text-based diagramming tool. It transforms structured ASCII diagrams and plain text sketches into clean, scalable vector graphics. The tool specializes in converting ASCII art and text-based scribbles into precise SVG paths, specifically for technical documentation and presentations. It supports the generation of directional arrows and structural diagrams by translating specific characters into vector lines, corners, and intersections. The system includes capabilities for rendering ASCII diagrams, generating vector graphics for technical guides, and es

drawio is a web-based diagramming tool and cross-platform visual designer used for creating flowcharts, network maps, and technical schemas. It functions as a vector graphics editor and an XML-based diagramming engine that allows users to design and export scalable graphics. The software supports a wide range of technical design tasks, including infrastructure mapping for server layouts and the creation of visual aids for technical documentation. It enables the import of diagram files from other tools to facilitate cross-tool migration.

This project is a cross-platform desktop application designed for creating, editing, and managing structured diagrams and technical workflows. It provides a visual modeling environment that allows users to construct complex charts through a drag-and-drop interface, supporting the documentation of processes, software architectures, and system flows. The application distinguishes itself by utilizing a layered canvas composition that enables independent manipulation of diagram components, paired with a keyboard-driven workflow that minimizes mouse reliance. It employs scalable vector graphics fo

Drawnix is a digital whiteboarding and visual diagramming application centered around an infinite canvas. It provides a workspace for freeform sketching, interactive brainstorming, and the creation of structured visual documentation. The platform distinguishes itself by supporting both manual drawing and the automatic generation of diagrams from markup text and mermaid syntax. It utilizes a plugin architecture that allows for the integration of custom modules to extend drawing behaviors and application features. The toolset includes brush-based annotations, image insertion, and a coordinate

X6 is a JavaScript diagramming library and SVG graph rendering engine used to build interactive flowcharts, mind maps, and visual workflow editors. It provides a framework for defining customizable node and edge behaviors, utilizing a hybrid rendering approach that combines SVG and HTML. The library decouples the visual graph representation from underlying business logic and data structures through a dedicated state management system. It allows for extensive extensibility via a registration mechanism for custom nodes, edges, and canvas tools. The toolkit includes capabilities for automatic g

FriendsDontLetFriends is a scientific data visualization guide and framework designed to help users create accurate plots while avoiding common data representation mistakes. It provides a collection of scripts and guidelines for selecting distribution plots, color scales, and layouts that accurately represent complex experimental data. The project distinguishes itself through specialized toolkits for revealing hidden patterns in large datasets. It includes systems for heatmap optimization via dimension reordering and outlier management, as well as spatial layout algorithms to improve the inte

Butterfly is an interactive graph visualization library and SVG-based diagramming engine used to build node-based workflow designers and visual flow editors. It provides a framework for rendering interconnected nodes, edges, and groups to model technical architectures, business processes, and data-driven workflows. The project is distinguished by its ability to integrate custom UI components as graph nodes and its specialized support for data lineage visualization. It enables the mapping of relationships between data fields, tables, and business entities to track provenance and monitor workfl

Pencil is a cross-platform design environment and vector drawing application used for GUI prototyping and diagramming. It provides a canvas-based editor to create interactive user interface mockups, system architecture diagrams, and scalable visual representations of technical flows. The tool functions as a vector graphic editor that renders shapes as mathematical paths to ensure scalability across different resolutions. It includes a PDF export layout engine specifically designed to convert screen-based visual designs into fixed-layout documents for physical printing and distribution. The p

yn is a markdown text editor and knowledge management tool designed as an interactive document canvas. It functions as a networked note-taking system for organizing information via wiki-links, hashtags, and local file repositories, while integrating an AI writing assistant for automated text generation and completion. The project is distinguished by its multi-engine diagramming capabilities, which render text-based syntax into visuals using Mermaid, PlantUML, and ECharts. It employs an extensible plugin framework that allows for the addition of custom UI elements and features through JavaScri

This project is a responsive Jekyll static site theme designed for technical blogs, documentation, and multilingual websites. It focuses on text readability and the presentation of technical content, providing a customizable CSS theme with multiple color palettes and dark mode toggling. The theme distinguishes itself through specialized rendering for technical assets, including mathematical formulas, diagrams, and syntax-highlighted code. It includes built-in internationalization support via translation keys to facilitate the creation of sites in multiple languages. The capability surface co

AndroidNote is a technical knowledge base and reference resource for Android development. It provides comprehensive guidance on application architecture, custom view development, and advanced graphics programming. The project is distinguished by its depth in visual implementation, covering pseudo-3D perspective projections via virtual cameras and complex 2D rendering using Bézier curves and PorterDuff color blending. It also provides detailed methodologies for app modularization and the management of internal libraries through private Maven repositories and JitPack. The reference surface ext