OfficeIMO - Open XML and document utilities for .NET

OfficeIMO is a family of COM-free .NET libraries for creating, reading, converting, and exporting Office and document-related formats. The main packages work directly with Open XML formats and are designed for server, desktop, CI, and PowerShell scenarios where Microsoft Office automation is not an option.

What is in this repo?

• Word: create, edit, inspect, and convert .docx documents
• Excel: create and modify .xlsx workbooks, worksheets, tables, ranges, styles, and reports
• PowerPoint: generate .pptx presentations programmatically
• Visio: create and validate basic .vsdx diagrams
• Markdown: typed Markdown AST, builder APIs, HTML rendering, renderer shells, and host plug-ins
• Markup: Markdown-inspired authoring for Word, Excel, and PowerPoint exports
• Reader: read-only extraction facade plus modular adapters for ingestion pipelines
• PDF, ZIP, EPUB, CSV, and Drawing primitives used across the OfficeIMO family
• Google Workspace bridges for Google Docs and Google Sheets export planning

Most packages are MIT licensed. OfficeIMO.Visio is a special case: the project file currently declares MIT package metadata, while the project folder still carries a restrictive LICENSE.MD; treat Visio licensing as unresolved until that conflict is corrected.

Project READMEs

Core document packages

• OfficeIMO.Word
• OfficeIMO.Excel
• OfficeIMO.PowerPoint
• OfficeIMO.Visio
• OfficeIMO.CSV
• OfficeIMO.Drawing
• OfficeIMO.Pdf
• OfficeIMO.Zip
• OfficeIMO.Epub

Conversion packages

• OfficeIMO.Word.Html
• OfficeIMO.Word.Markdown
• OfficeIMO.Word.Pdf
• OfficeIMO.Excel.Pdf
• OfficeIMO.Markdown.Html

Markdown and rendering packages

• OfficeIMO.Markdown
• OfficeIMO.MarkdownRenderer
• OfficeIMO.MarkdownRenderer.Wpf
• OfficeIMO.MarkdownRenderer.IntelligenceX
• OfficeIMO.MarkdownRenderer.SamplePlugin
• OfficeIMO.Markdown.Benchmarks

Reader and ingestion packages

• OfficeIMO.Reader
• OfficeIMO.Reader.Csv
• OfficeIMO.Reader.Epub
• OfficeIMO.Reader.Html
• OfficeIMO.Reader.Json
• OfficeIMO.Reader.Text
• OfficeIMO.Reader.Xml
• OfficeIMO.Reader.Zip

Authoring and export packages

• OfficeIMO.Markup
• OfficeIMO.Markup.Word
• OfficeIMO.Markup.Excel
• OfficeIMO.Markup.PowerPoint
• OfficeIMO.Markup.Cli

Google Workspace packages

• OfficeIMO.GoogleWorkspace
• OfficeIMO.Word.GoogleDocs
• OfficeIMO.Excel.GoogleSheets

Examples, benchmarks, and release notes

• OfficeIMO.Examples
• OfficeIMO.Excel.Benchmarks
• Docs/officeimo.pdf.current-state.md
• Docs/officeimo.excel.release-checklist.md
• Docs/officeimo.markdown.release-checklist.md
• CHANGELOG.MD

Website

• Public site content and GitHub Pages deployment live under Website/
• Maintainer notes for the website pipeline and API ingestion live in Docs/officeimo.website.md

Package families

Word family

• OfficeIMO.Word: main Word document object model
• OfficeIMO.Word.Html: Word to/from HTML conversion helpers
• OfficeIMO.Word.Markdown: Word to/from Markdown conversion helpers
• OfficeIMO.Word.Pdf: Word to PDF export through the first-party OfficeIMO.Pdf engine

Excel family

• OfficeIMO.Excel: workbook, worksheet, table, range, style, and reporting helpers
• OfficeIMO.Excel.Pdf: Excel workbook to PDF export through the first-party OfficeIMO.Pdf engine
• OfficeIMO.Excel.GoogleSheets: Excel to Google Sheets planning, batch compilation, and export helpers
• OfficeIMO.Excel.Benchmarks: benchmark harness for Excel package behavior

Google Workspace family

• OfficeIMO.GoogleWorkspace: shared credentials, session, Drive location, retry, and translation-report abstractions
• OfficeIMO.Word.GoogleDocs: Word to Google Docs planning, batch compilation, and export helpers
• OfficeIMO.Excel.GoogleSheets: Excel to Google Sheets planning, batch compilation, and export helpers

Markdown family

• OfficeIMO.Markdown: Markdown builder, typed reader/AST, HTML renderer, front matter, TOC, callouts, and query helpers
• OfficeIMO.Markdown.Html: HTML-to-Markdown AST bridge targeting the OfficeIMO Markdown document model
• OfficeIMO.MarkdownRenderer: WebView/browser-friendly rendering shell and incremental update helpers
• OfficeIMO.MarkdownRenderer.Wpf: reusable WPF/WebView2 MarkdownView host
• OfficeIMO.MarkdownRenderer.IntelligenceX: first-party IntelligenceX renderer feature pack
• OfficeIMO.MarkdownRenderer.SamplePlugin: sample renderer plug-in package
• OfficeIMO.Markdown.Benchmarks: representative parse/render benchmark harness

Markup family

• OfficeIMO.Markup: Markdown-inspired semantic authoring layer for OfficeIMO documents
• OfficeIMO.Markup.Word: Word exporter for markup documents
• OfficeIMO.Markup.Excel: Excel exporter for markup workbooks
• OfficeIMO.Markup.PowerPoint: PowerPoint exporter for markup presentations
• OfficeIMO.Markup.Cli: command-line parser, validator, emitter, and exporter

Reader family

• OfficeIMO.Reader: read-only facade for deterministic ingestion
• OfficeIMO.Reader.Csv: CSV adapter
• OfficeIMO.Reader.Epub: EPUB adapter
• OfficeIMO.Reader.Html: HTML adapter through the Markdown HTML bridge
• OfficeIMO.Reader.Json: JSON adapter
• OfficeIMO.Reader.Text: structured text compatibility adapter
• OfficeIMO.Reader.Xml: XML adapter
• OfficeIMO.Reader.Zip: ZIP adapter

Other packages

• OfficeIMO.CSV: typed CSV read/write and schema workflows
• OfficeIMO.Drawing: first-party color and image metadata primitives
• OfficeIMO.Pdf: dependency-free PDF builder, reader, page inspector, page extractor, page editor, metadata editor, merger, and future first-party PDF engine
• OfficeIMO.PowerPoint: programmatic PowerPoint slide generation
• OfficeIMO.Visio: basic Visio diagram generation and validation
• OfficeIMO.Zip: safe ZIP traversal primitives
• OfficeIMO.Epub: EPUB extraction primitives

Target frameworks

Most shipping libraries target netstandard2.0, net8.0, and net10.0. Many projects also add net472 when building on Windows, which preserves .NET Framework support without making that target the cross-platform baseline.

Important exceptions:

• OfficeIMO.CSV includes net472 directly.
• OfficeIMO.MarkdownRenderer.Wpf targets net472, net8.0-windows, and net10.0-windows for the WPF/WebView2 surface, plus non-Windows net8.0 and net10.0 helper targets.
• CLI, benchmark, example, and test projects generally target modern .NET only.

AOT and trimming

• Reflection-heavy convenience APIs remain available for dynamic and PowerShell scenarios.
• For trimming-sensitive workloads, prefer typed overloads and explicit selectors.
• OfficeIMO.Markdown, OfficeIMO.CSV, OfficeIMO.Drawing, OfficeIMO.Pdf, OfficeIMO.Zip, and OfficeIMO.Epub are the lightest dependency shapes.
• Open XML-heavy packages should be tested against the exact publish options and document features your application uses.
• OfficeIMO.Word.Pdf and OfficeIMO.Excel.Pdf should be treated separately because PDF layout fidelity and host fonts still need scenario validation.

Dependencies at a glance

Arrows point from a package to what it depends on. Test, benchmark, and example-only dependencies are intentionally excluded unless called out.

Word and conversion

flowchart TB
  Word["OfficeIMO.Word"]
  Drawing["OfficeIMO.Drawing"]
  WordHtml["OfficeIMO.Word.Html"]
  WordMarkdown["OfficeIMO.Word.Markdown"]
  WordPdf["OfficeIMO.Word.Pdf"]
  Markdown["OfficeIMO.Markdown"]
  MarkdownHtml["OfficeIMO.Markdown.Html"]
  OpenXml["DocumentFormat.OpenXml"]
  Angle["AngleSharp"]
  AngleCss["AngleSharp.Css"]
  Pdf["OfficeIMO.Pdf"]

  Word --> Drawing
  Word --> OpenXml
  WordHtml --> Word
  WordHtml --> Drawing
  WordHtml --> OpenXml
  WordHtml --> Angle
  WordHtml --> AngleCss
  WordMarkdown --> Word
  WordMarkdown --> WordHtml
  WordMarkdown --> Markdown
  WordMarkdown --> MarkdownHtml
  WordMarkdown --> Drawing
  WordPdf --> Word
  WordPdf --> Pdf

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Excel, PowerPoint, Visio, and primitives

flowchart TB
  Excel["OfficeIMO.Excel"]
  ExcelPdf["OfficeIMO.Excel.Pdf"]
  PowerPoint["OfficeIMO.PowerPoint"]
  Visio["OfficeIMO.Visio"]
  Drawing["OfficeIMO.Drawing"]
  OpenXml["DocumentFormat.OpenXml"]
  Packaging["System.IO.Packaging"]
  Csv["OfficeIMO.CSV"]
  Pdf["OfficeIMO.Pdf"]
  Zip["OfficeIMO.Zip"]
  Epub["OfficeIMO.Epub"]

  Excel --> Drawing
  Excel --> OpenXml
  ExcelPdf --> Excel
  ExcelPdf --> Pdf
  PowerPoint --> OpenXml
  Visio --> Drawing
  Visio --> Packaging

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OfficeIMO.CSV, OfficeIMO.Drawing, OfficeIMO.Pdf, OfficeIMO.Zip, and OfficeIMO.Epub are dependency-light first-party packages. Color and image metadata live in OfficeIMO.Drawing, and Excel text measurement is handled by first-party code.

Markdown, renderer, and markup

flowchart TB
  Markdown["OfficeIMO.Markdown"]
  MarkdownHtml["OfficeIMO.Markdown.Html"]
  Renderer["OfficeIMO.MarkdownRenderer"]
  RendererWpf["OfficeIMO.MarkdownRenderer.Wpf"]
  RendererIx["OfficeIMO.MarkdownRenderer.IntelligenceX"]
  RendererSample["OfficeIMO.MarkdownRenderer.SamplePlugin"]
  Markup["OfficeIMO.Markup"]
  MarkupWord["OfficeIMO.Markup.Word"]
  MarkupExcel["OfficeIMO.Markup.Excel"]
  MarkupPowerPoint["OfficeIMO.Markup.PowerPoint"]
  MarkupCli["OfficeIMO.Markup.Cli"]
  Word["OfficeIMO.Word"]
  Excel["OfficeIMO.Excel"]
  PowerPoint["OfficeIMO.PowerPoint"]
  Angle["AngleSharp"]
  Json["System.Text.Json"]
  WebView2["Microsoft.Web.WebView2"]

  MarkdownHtml --> Markdown
  MarkdownHtml --> Angle
  Renderer --> Markdown
  Renderer --> MarkdownHtml
  Renderer --> Json
  RendererWpf --> Renderer
  RendererWpf --> WebView2
  RendererIx --> Renderer
  RendererIx --> MarkdownHtml
  RendererSample --> Renderer
  RendererSample --> MarkdownHtml
  RendererSample --> Json
  Markup --> Markdown
  MarkupWord --> Markup
  MarkupWord --> Word
  MarkupExcel --> Markup
  MarkupExcel --> Excel
  MarkupPowerPoint --> Markup
  MarkupPowerPoint --> PowerPoint
  MarkupCli --> Markup
  MarkupCli --> MarkupWord
  MarkupCli --> MarkupExcel
  MarkupCli --> MarkupPowerPoint

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Reader and Google Workspace

flowchart TB
  Reader["OfficeIMO.Reader"]
  ReaderCsv["OfficeIMO.Reader.Csv"]
  ReaderEpub["OfficeIMO.Reader.Epub"]
  ReaderHtml["OfficeIMO.Reader.Html"]
  ReaderJson["OfficeIMO.Reader.Json"]
  ReaderText["OfficeIMO.Reader.Text"]
  ReaderXml["OfficeIMO.Reader.Xml"]
  ReaderZip["OfficeIMO.Reader.Zip"]
  Word["OfficeIMO.Word"]
  WordMarkdown["OfficeIMO.Word.Markdown"]
  Excel["OfficeIMO.Excel"]
  PowerPoint["OfficeIMO.PowerPoint"]
  Markdown["OfficeIMO.Markdown"]
  Pdf["OfficeIMO.Pdf"]
  Csv["OfficeIMO.CSV"]
  Epub["OfficeIMO.Epub"]
  Zip["OfficeIMO.Zip"]
  MarkdownHtml["OfficeIMO.Markdown.Html"]
  Google["OfficeIMO.GoogleWorkspace"]
  GoogleDocs["OfficeIMO.Word.GoogleDocs"]
  GoogleSheets["OfficeIMO.Excel.GoogleSheets"]
  Json["System.Text.Json"]

  Reader --> Word
  Reader --> WordMarkdown
  Reader --> Excel
  Reader --> PowerPoint
  Reader --> Markdown
  Reader --> Pdf
  Reader --> Json
  ReaderCsv --> Reader
  ReaderCsv --> Csv
  ReaderEpub --> Reader
  ReaderEpub --> Epub
  ReaderHtml --> Reader
  ReaderHtml --> MarkdownHtml
  ReaderJson --> Reader
  ReaderJson --> Json
  ReaderText --> Reader
  ReaderText --> ReaderCsv
  ReaderText --> ReaderJson
  ReaderText --> ReaderXml
  ReaderXml --> Reader
  ReaderZip --> Reader
  ReaderZip --> Zip
  GoogleDocs --> Google
  GoogleDocs --> Word
  GoogleDocs --> Json
  GoogleSheets --> Google
  GoogleSheets --> Excel
  GoogleSheets --> Json

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When do I need what?

• Creating or editing Word documents: add OfficeIMO.Word
• Word to HTML: add OfficeIMO.Word and OfficeIMO.Word.Html
• Word to Markdown or Markdown to Word: add OfficeIMO.Word, OfficeIMO.Word.Markdown, and the Markdown packages it references
• Word to PDF: add OfficeIMO.Word and OfficeIMO.Word.Pdf
• Creating Excel workbooks and reports: add OfficeIMO.Excel
• Excel to PDF: add OfficeIMO.Excel and OfficeIMO.Excel.Pdf
• Creating PowerPoint decks: add OfficeIMO.PowerPoint
• Creating Visio diagrams: add OfficeIMO.Visio
• Working directly with Markdown: add OfficeIMO.Markdown
• Hosting Markdown in a browser/WebView shell: add OfficeIMO.MarkdownRenderer
• Hosting Markdown in a WPF app: add OfficeIMO.MarkdownRenderer.Wpf
• Adding IntelligenceX-oriented renderer behavior: add OfficeIMO.MarkdownRenderer.IntelligenceX
• Authoring Office files from .omd markup: use OfficeIMO.Markup plus the Word, Excel, or PowerPoint exporter package
• Ingesting documents for indexing, chat, or search: add OfficeIMO.Reader and only the adapter packages your host needs
• Shared Google Workspace session/auth primitives: add OfficeIMO.GoogleWorkspace
• Word to Google Docs planning/export: add OfficeIMO.Word and OfficeIMO.Word.GoogleDocs
• Excel to Google Sheets planning/export: add OfficeIMO.Excel and OfficeIMO.Excel.GoogleSheets
• CSV schemas and typed CSV workflows: add OfficeIMO.CSV
• Dependency-light PDF generation without Word conversion: add OfficeIMO.Pdf
• Safe ZIP or EPUB traversal/extraction primitives: add OfficeIMO.Zip or OfficeIMO.Epub

Dependency versions, high level

• DocumentFormat.OpenXml: [3.5.1, 4.0.0) in the Open XML packages that reference it
• OfficeIMO.Drawing: first-party color and image metadata helpers
• AngleSharp / AngleSharp.Css: HTML parsing and CSS conversion layers
• OfficeIMO.Pdf: first-party Word/Excel-to-PDF conversion engine and dependency-light PDF primitives
• System.Text.Json: reader, renderer, and Google Workspace helper surfaces on legacy target frameworks
• Microsoft.Web.WebView2: WPF Markdown renderer host
• System.IO.Packaging: Visio package handling

See each project .csproj for exact package ranges.

Support this project

If you find this project helpful, please consider supporting its development. Sponsorship helps the maintainers spend more time on maintenance, documentation, tests, and new features.

• Become a sponsor via GitHub Sponsors
• Become a sponsor via PayPal

Sponsorship is optional. OfficeIMO remains open source and available for anyone to use regardless of sponsorship.

Please share with the community

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