Open-source alternatives to Responsive Html Email Template

Heml is a framework providing a custom markup language and compiler designed to generate responsive HTML and CSS for consistent rendering across email clients. It functions as a system for transforming specialized markup strings into deliverable email templates and associated metadata. The project features a component system for defining reusable custom elements and style rules to standardize design patterns. It includes a responsive layout engine that converts flexible grid structures, columns, and rows into compatible fixed-width tables and fluid layouts. The toolset covers email metadata

Email-Blueprints is a modular email framework and HTML template library used to assemble custom email structures from a collection of reusable design patterns and blocks. It provides a system of flexible components for creating consistent email designs across diverse clients. The framework enables the creation of responsive layouts that adapt to various screen sizes and fixed-width designs for legacy email client compatibility. It also supports dynamic content templates that utilize merge tags to inject recipient-specific data for personalization. The project covers the development of cross-

Email-Boilerplate is an HTML email template framework and design system providing a foundational code structure for developing newsletters and transactional emails. It serves as a cross-client email layout library designed to ensure consistent rendering across diverse desktop and mobile email applications. The project utilizes a table-based layout library and reusable code patterns to maintain structural integrity within restrictive email rendering engines. It employs a responsive design system that combines fluid hybrid scaling and semantic markup normalization to resolve common rendering in

CssToInlineStyles is a CSS inliner for HTML emails that converts stylesheets into inline style attributes on HTML elements. It functions as a style resolver and transformation engine, mapping CSS selectors to HTML tags to ensure consistent visual rendering across diverse email clients and providers. The tool calculates final computed styles by applying specificity and inheritance rules before injecting the resolved properties directly into the style attributes of the corresponding HTML elements. It utilizes DOM-based style calculation and selector mapping to determine which declarations apply

React Email is a development framework for designing and testing HTML emails using a library of modular components. It provides a set of reusable UI primitives that allow developers to build email templates through declarative code, ensuring consistent visual presentation across various desktop and mobile email service providers. The framework functions by transforming component trees into static HTML markup, automatically handling the complex requirements of email client rendering. It includes a built-in engine that extracts style declarations and injects them directly into HTML elements, by

MJML is a responsive email framework and HTML email compiler that translates simplified semantic markup into complex HTML. It functions as an email template engine designed to produce layouts that render consistently across a wide range of email clients. The system provides a markup validation tool to check structural integrity and syntax before compilation. It also includes a version migration utility to upgrade older template files to newer language versions while preserving content and layout structure. The toolset covers several capability areas, including command-line markup compilation

Neat is a Sass grid framework and responsive layout system used to build fluid, column-based web architectures. It provides a structured approach to managing layout properties and global design settings through a central configuration map and a toolset of Sass mixins and functions. The system is distinguished by its ability to handle nested grid architectures, allowing flexible grids to be placed inside other grid containers while maintaining precise alignment and gutter control. It also includes development tools for frontend layout debugging that render background guide lines to visualize c

Skeleton is a lightweight responsive CSS boilerplate and mobile-first framework. It provides a foundation for building mobile-friendly websites through a fluid 12-column grid system, a minimal CSS reset library to normalize browser defaults, and default styling for raw HTML elements. The project emphasizes a mobile-first development approach, using percentage-based widths and predefined media queries to progressively enhance layouts for larger screens. It includes a utility-first library of single-purpose classes to manage common layout tasks such as floating elements, clearing, and width con

This project is a visual HTML email builder and responsive design tool used to create mobile-ready email layouts. It includes a dynamic email template engine and an artificial intelligence generator for drafting email copy and structural layouts. The system utilizes a component-based layout engine to build emails using standardized blocks and columns, which are translated into table-based HTML for compatibility across diverse email clients. It supports personalization through variable-based template interpolation and conditional logic to adjust content based on specific data sets. The platfo

Flexboxgrid is a responsive CSS framework and layout engine based on CSS3 standards. It provides a grid system that uses the flexbox model to arrange page elements into flexible, proportional grids that adapt to different screen sizes and device resolutions. The framework implements a float-free responsive design, utilizing a media-query breakpoint system to adjust layouts and column counts based on viewport width. It employs percentage-based column sizing and negative-margin guttering to maintain consistent spacing and fluid scaling across various displays. The system maps layout configurat

This project is an HTML email framework and compiler designed to build responsive emails using a high-level syntax that transforms into table-based layouts. It functions as an HTML-to-table compiler and CSS inliner, ensuring that simplified markup is converted into the complex nested structures and inline attributes required for cross-client compatibility. The framework features a responsive email grid system and Sass-based styling, allowing the use of variables to manage colors, typography, and spacing. These tools enable custom brand theming and the creation of fluid layouts that adapt to v

Pure is a CSS UI framework and modular component library designed for building consistent web layouts and interface components. It functions as a responsive CSS grid system and a CSS reset library that normalizes default browser rendering to ensure a uniform appearance across different web environments. The project provides standalone styles for common interactive elements such as buttons, menus, forms, and tables. It utilizes a modular architecture that allows for the inclusion of specific style modules and employs namespace isolation to prevent visual conflicts between components. The fram

Mailpit is an SMTP mail testing server and web-based email inbox designed to intercept and store outgoing emails for development and integration testing without delivering them to real recipients. It functions as an SMTP mocking tool and relay gateway, allowing users to capture mail traffic and view it through a browser interface. The project distinguishes itself by providing tools for SMTP server simulation, including the ability to inject failure codes to test application resilience. It also includes an email compatibility analyzer that validates HTML rendering, checks link integrity, and s

WooCommerce is a comprehensive eCommerce framework for WordPress that transforms websites into fully functional online stores for physical and digital goods. It serves as a digital storefront manager for product catalogs, inventory, and customer orders across retail and wholesale business models. The system functions as a payment gateway integrator, connecting shops to diverse processors for credit cards, digital wallets, and subscriptions. It also operates as an order fulfillment system for calculating shipping rates, generating labels, and coordinating delivery via third-party couriers, whi

Quarkus is a Kubernetes-native Java framework designed for building high-performance, memory-efficient applications. It utilizes ahead-of-time native compilation to transform Java code into standalone, optimized binaries that eliminate the need for a virtual machine, enabling rapid startup and reduced memory consumption. By performing code augmentation during the build phase, it shifts heavy processing tasks away from runtime, ensuring that applications are optimized for cloud-native environments. The framework distinguishes itself through a unified approach to reactive and imperative program

Mailtrain is a self-hosted newsletter platform and email marketing tool designed for managing subscriber lists and sending automated email campaigns from a private server. It provides a centralized system for coordinating the creation and delivery of recurring email outreach. The platform includes a visual email template builder for creating responsive layouts and a subscriber management system that uses custom fields to organize audiences into targeted segments. Automation is handled through tools that can trigger newsletters based on remote feeds and scheduled events. Performance is tracke

Masonry is a JavaScript library for arranging elements of varying heights into a grid without vertical gaps. It serves as a DOM element positioner and dynamic layout manager that calculates and applies absolute coordinates to HTML elements based on available vertical space. The system functions as a responsive grid engine using percentage-based widths to maintain consistent structures across different screen sizes. It includes capabilities to recalculate grid positions after images load or browser windows resize to prevent element overlap. The library covers grid management and positioning,

This project is a Node.js email templating engine and SMTP delivery framework used for creating, rendering, and sending custom email templates. It provides a comprehensive suite for email orchestration, including a system for dispatching templated messages and a tool for generating custom layouts to standardize outbound messaging. The framework includes a dedicated HTML CSS inliner that converts external stylesheets into inline styles for consistent rendering across different email clients. It also features a multilingual localization tool for translating template text and subject lines, and

React Email Editor is a drag-and-drop visual builder for creating responsive email templates, built as a React embeddable component. It also serves as an AI-powered email designer, a collaborative email design tool, and a React component library for composing emails programmatically with JSX. The editor represents designs as structured JSON and supports multi-format rendering for email clients, web pages, and PDF. What distinguishes this editor is its deep AI integration: users can generate full email templates from natural language, rewrite text with chosen intent, produce multiple text vari

Nodemailer is a comprehensive library for Node.js applications designed to handle the composition, signing, and transmission of email messages. It provides a robust framework for constructing MIME-compliant content, managing complex attachments, and routing messages through various delivery channels, including standard SMTP servers, local mail transfer agents, and cloud-based email services. The library distinguishes itself through a modular, plugin-based transport architecture that allows for custom delivery mechanisms and environment-specific configurations. It includes advanced features fo

SuperAGI is a comprehensive marketing automation platform and customer data system designed to orchestrate multi-channel engagement workflows. It functions as a no-code workflow orchestrator, allowing users to build complex, automated task sequences triggered by real-time user behavior, transactional data, or scheduled events. By centralizing customer profiles and interaction history, the platform enables businesses to manage end-to-end marketing operations from a single interface. The platform distinguishes itself through its deep integration with e-commerce storefronts and its ability to ex

Termui is a Go terminal user interface library used for building interactive dashboards and visual layouts within a command-line environment. It functions as a TUI layout engine, an interactive CLI framework, and a terminal data visualization toolkit. The library provides a set of specialized widgets for rendering charts, plots, gauges, and tables using character-based graphics. It includes a grid-based system for arranging interface elements using relative coordinates and proportional sizing to create structured displays. The toolkit covers a broad range of capabilities including data visua

This project is a React component library and web UI design system designed for creating interactive web interfaces. It functions as a responsive frontend framework that provides a collection of modular building blocks to ensure visual consistency across different application pages and devices. The system utilizes a CSS-in-JS styling framework that generates and injects styles at runtime through a centralized property injection system. This approach allows for the implementation of a theme-driven architecture where layouts and color themes automatically adjust based on screen size and user pr

Basscss is a lightweight CSS utility toolkit built on an atomic, single-purpose class architecture. Each class performs exactly one visual function, enabling immutable, side-effect-free styling where no class ever overrides or conflicts with another. The system provides a predefined spacing scale, responsive breakpoint prefixes for conditional styling across device widths, and accessible visibility control that keeps content programmatically available to assistive technologies. The framework distinguishes itself through a float-based grid system that constructs layouts using floated percentag

Glide is a dependency-free ES6 JavaScript library used to create responsive content sliders and carousels. It functions as a modular framework for implementing sliding content areas that adapt their layout and settings based on browser window breakpoints. The library is distinguished by a modular architecture that allows the inclusion of only necessary logic to reduce final bundle size. It separates core structural styles from thematic visual styles and utilizes a plugin system to extend the base slider functionality and lifecycle hooks. The component covers a range of interaction and naviga

Foundation Sites is a responsive front-end framework providing a collection of CSS and JavaScript tools to build websites that automatically adapt to different screen sizes and devices. It functions as a responsive design library and cross-browser UI toolkit, offering a grid layout system and pre-styled interface components to ensure consistent rendering across modern web browsers. The framework enables rapid front-end UI prototyping and the integration of interactive components through a scripting interface that manages the lifecycle of UI plugins. It supports custom CSS framework management

Embla Carousel is a lightweight JavaScript carousel library and barebones slider engine designed for creating touch-enabled, swipeable content sliders. It functions as a plugin-based framework that manages scroll physics and slide positioning without imposing specific UI styles, while providing a programmable API for custom carousel development. The system is distinguished by its modular architecture, allowing developers to extend core logic through external plugins and custom event hooks. It is compatible with server-side rendering, generating initial styles on the server to prevent layout s