Open-source alternatives to Open XML SDK

Nokogiri is an XML and HTML parsing library that builds navigable document trees from strings, files, or URLs using native C parsers for speed and standards compliance. It provides a CSS selector engine that translates CSS3 selectors into XPath expressions for querying nodes, an XPath query interface with namespace support, a document manipulation toolkit for modifying parsed documents, XSD schema validation, and XSLT transformation capabilities. The library wraps libxml2 and libxslt C libraries with Ruby bindings for high-performance parsing, and integrates Google's Gumbo parser for standard

pugixml is a lightweight C++ XML parser and DOM-based library used for parsing, manipulating, and saving XML documents. It provides a portable toolset for reading XML data from files, strings, or memory buffers and converting them into an in-memory document object model. The library includes a dedicated XPath 1.0 engine for extracting specific nodes and data through path expressions. It distinguishes itself through customizable memory management, allowing heap operations to be redirected to user-defined allocation functions, and the ability to perform in-place buffer parsing to reduce memory

htmlparser2 is a collection of tools for high-performance markup parsing, DOM manipulation, and incremental stream processing. It functions as an HTML and XML parser that converts markup strings into structured object trees, alongside a streaming markup parser designed for memory-efficient processing of large documents. The project includes a DOM manipulation library for querying, modifying, and serializing document object model trees. It also provides a web feed parser to extract structured metadata and entries from RSS, RDF, and Atom feeds. The library covers broad capabilities in data par

xmltodict is a Python library that provides bidirectional serialization between XML documents and dictionaries. It functions as a parser that converts marked-up input into key-value pairs and a serialization utility that transforms dictionaries back into structured XML documents. The project includes an incremental stream processor that uses depth-based callbacks to handle large XML files while maintaining constant memory usage. It features a namespace manager for mapping prefixes and declarations, as well as a security sanitizer that blocks external entity expansion and validates element nam

parse5 is a WHATWG HTML parser and serializer for Node.js. It transforms HTML strings into a document object model and converts those trees back into valid HTML strings, following the logic defined by the HTML Living Standard. The project functions as a streaming HTML processor, using incremental parsing to handle large documents in chunks. It includes an HTML5 compliant tokenizer that uses a state-machine approach to break input into tokens according to official web specifications. The toolset covers HTML document parsing, serialization, and real-time rewriting via streams. These capabiliti

Docxtemplater is an office document generation engine designed to automate the creation of personalized business documents, presentations, and spreadsheets. By manipulating the underlying XML structure of office files, the framework replaces placeholders within pre-designed templates with dynamic data, enabling the programmatic production of reports, invoices, and complex data-driven documents. The project distinguishes itself through a modular extension architecture that allows developers to integrate custom logic for handling images, charts, and specialized formatting. It supports advanced

NPOI is a pure .NET library for reading and writing Microsoft Office files in both legacy binary (.xls) and modern OpenXML (.xlsx, .docx) formats, operating entirely without requiring Microsoft Office or COM interop. It runs on Windows and Linux under .NET Standard and .NET Framework runtimes, using only managed code to parse and generate Office documents. The library provides comprehensive spreadsheet capabilities, including creating, editing, and reading Excel workbooks in both .xls and .xlsx formats, with support for cell formatting, styles, and formulas. It includes a streaming row-by-row

This project is an HTML and XML DOM parser designed for loading and navigating the structure of web documents to extract specific data points. It functions as a web scraping utility that provides a system for locating precise elements using a CSS and XPath selector engine. The library includes a URI resolver that converts relative links found in documents into absolute addresses using a base URI. It provides a set of tools for retrieving text, attributes, and media sources from parsed content. The toolset covers document hierarchy traversal, selector-based filtering, and text extraction with

OfficeCLI is a headless office suite and automation tool designed for programmatically reading, editing, and generating Microsoft Office documents. It functions as an OOXML manipulation library and a document templating engine, providing a standalone binary that allows for the management of Word, Excel, and PowerPoint files without requiring a local installation of office software. The project distinguishes itself by exposing document operations as tools for AI agents via a JSON-RPC server and the Model Context Protocol. It enables advanced customization through raw XML manipulation using XPa

SwiftSoup is a cross-platform HTML processing library for Swift that converts raw HTML or XML strings and files into a structured document object model. It provides the core infrastructure to parse web content into a traversable tree, enabling programmatic access to page elements across iOS, macOS, and Linux. The library features a CSS selector engine for data extraction and a whitelist-based sanitization system to remove unsafe tags and attributes from user-submitted content. It optimizes repetitive document queries through memoized query caching. The project covers DOM manipulation for upd

Jodd is a suite of lightweight Java extensions and standard library utilities designed for application configuration, database mapping, dependency injection, and HTML parsing. It provides a consolidated set of core tools to facilitate Java development with a zero-dependency core to ensure compatibility and a small footprint across environments. The project features a pragmatic dependency injection container for managing object lifecycles and a database mapper that uses SQL templates to map result sets directly to Java objects. It includes a specialized configuration manager supporting profile

TinyXML-2 is a lightweight C++ library for parsing, manipulating, and generating XML documents. It functions as a UTF-8 XML processor that represents data through a hierarchical Document Object Model. The library provides tools for both DOM parsing and direct document generation via data streams. It includes capabilities for navigating the XML tree to locate specific elements, modifying attributes and content, and resolving character entities and Unicode numeric references into UTF-8 text. The processor includes syntax validation and diagnostic utilities that track line-number metadata for e

Gosub-engine is an HTML5 browser engine and web rendering pipeline that parses HTML5 and CSS3 to compute layout and render web content to pixels. It functions as a JavaScript runtime environment with a virtual machine and event loop for handling dynamic logic and asynchronous tasks. The system also includes a web storage manager for persisting cookies, local storage, and session storage. The project features a headless browser renderer capable of generating page images or extracting plain text without a visible window. It supports cross-platform graphics rendering through pluggable CPU and GP

This project is a Node.js web scraping framework designed to automate data extraction through a programmatic workflow of requests, parsing, and document interaction. It functions as a headless web crawler, an HTTP request manager, and a DOM parser and extractor. The framework distinguishes itself by combining a JavaScript execution engine to interact with dynamic content and a hybrid selection system that utilizes both CSS and XPath selectors. It includes specialized middleware for proxy rotation and cookie-jar session management to maintain authenticated states and manage automated traffic.

jsdom is a Node.js implementation of web standards that functions as a headless browser emulator. It provides a JavaScript execution environment and an HTML and XML parser to simulate a browser environment on the server side, implementing various web APIs and W3C standards. The project distinguishes itself by providing a sandboxed runtime for executing scripts embedded in HTML or external files. It includes specialized polyfills for the Canvas API and manages session state through HTTP cookie management. Its broader capabilities cover network interaction via request interception and resource

PHPExcel is a PHP spreadsheet library used for programmatically reading and writing spreadsheet files in various formats. It utilizes an in-memory spreadsheet model that maps spreadsheet structures to a hierarchy of objects for programmatic manipulation. The library functions as an Office Open XML processor for generating and manipulating XLSX documents and serves as a reader for extracting data and structure from legacy binary XLS files. It also includes tools for CSV data integration and importing. The project provides capabilities for automated report generation and spreadsheet data extra

goquery is a Go HTML parsing library and CSS selector engine used to isolate and retrieve specific text or attributes from HTML documents. It functions as an HTML DOM manipulator that converts raw HTML strings into a structured tree for programmatic navigation and search. The library provides a fluent interface for chaining selection and filtering operations and utilizes a wrapper-based abstraction to simplify data extraction and manipulation of nodes. It employs an iterator-based processing mechanism to apply operations to every node within a matched selection. Its primary capabilities cove

docx is a JavaScript and TypeScript library for the programmatic generation and manipulation of Word documents. It serves as an OOXML document generator, allowing developers to create formatted office files through code instead of manual editing. The library enables document automation across both Node.js and web browser environments. It supports client-side document export, allowing users to generate and download files directly in the browser without a backend server. Capabilities include the ability to define page layouts, margins, and orientation. Users can programmatically insert documen

vue-office is an office document preview library and web-based document viewer designed to render Word, Excel, PowerPoint, and PDF files directly in a web browser. It provides a collection of reusable components that allow for the display of documents using network URLs, data buffers, or blob data without requiring external plugins. This rendering solution is built as a cross-framework document renderer, offering integration for Vue 2, Vue 3, and React. It enables client-side document display to avoid server-side conversion processes. The library handles document visualization through client

ONLYOFFICE DocumentServer is a self-hosted online office suite that provides browser-based document, spreadsheet, and presentation editing with real-time collaborative capabilities. It natively supports Office Open XML formats (.docx, .xlsx, .pptx) and can be deployed on Linux servers, either through Docker containerization or direct installation. The server includes a cooperative editing engine that coordinates simultaneous changes across multiple users using operational transformation, with a WebSocket synchronization layer for instant state propagation. Security is handled through JWT auth

Spout is a spreadsheet file processing library and multi-format generator designed for reading and writing CSV, XLSX, and ODS files. It functions as a stream-based parser that processes large spreadsheet files incrementally to avoid loading entire documents into memory. The library provides capabilities for programmatic spreadsheet generation and data extraction. It supports custom content styling, allowing for the application of fonts, backgrounds, borders, and number formats to individual cells or rows. Beyond basic file input and output, the project covers workbook manipulation through se

CsvHelper is a library for reading and writing comma-separated value files by mapping data to custom class objects. It functions as a parsing library and data mapper that converts flat-file text into structured data objects and serializes internal data sets back into standard CSV files. The project emphasizes memory efficiency through a parser that optimizes resource consumption. It utilizes field value caching and an interned string cache to store repetitive values, which reduces memory overhead when processing large datasets. The library provides a configuration-driven parsing engine that

EasyExcel is a Java processing library designed for reading and writing XLS, XLSX, and CSV files. It functions as a memory-efficient spreadsheet parser, an object-relational mapper that binds spreadsheet columns to Java class fields, and a stream-based exporter for handling high-volume data. The library distinguishes itself through a streaming model that processes large files row-by-row via listeners to prevent heap memory overflow. It also operates as a template engine, allowing the population of predefined spreadsheet files with dynamic data while preserving original layouts and styles. Br

This project is a Node.js library for bidirectional conversion between XML strings and JavaScript objects. It functions as an XML parser that transforms XML content into structured data and an XML serializer that generates formatted strings from JavaScript data objects. The toolkit includes a data transformer that applies custom processing functions to tags and attributes during the conversion process. It manages XML namespaces and supports the definition of custom root elements to maintain document structure during generation. The system handles XML data parsing, string generation, and name

This project is a centralized repository of XML definitions used to automate the formatting of bibliographic citations and references for scholarly publications. It functions as a declarative citation framework that maps bibliographic metadata to visual output using a schema-driven system rather than procedural code. The library provides a comprehensive collection of standardized formatting rules and locale files used to render academic citations according to specific journal or publisher requirements. It includes a bibliographic localization framework that adapts dates, punctuation, and term

SVGKit is a graphics framework for the iOS and macOS ecosystems designed for rendering high-performance scalable vector graphics. It functions as a library that utilizes native hardware acceleration to display and interact with vector graphics on Apple platforms. The project provides a programmatic interface for editing vector elements and writing updated files back to disk. It also includes tools to convert vector graphics into rasterized bitmap image formats for use in standard image views. The framework handles the translation of XML-based documents into a hierarchy of hardware-accelerate

Gop is a general purpose programming language and cross-language compiler designed to unify assets and libraries from multiple programming ecosystems into a single shared environment. It translates high-level source code into executable binaries using specialized backends tailored for different target environments. The project features a system for natural language programming, transforming human-readable instructions written in plain English into executable code. It also functions as a cross-language tool that imports and integrates external libraries and assets from different language ecosy