OfficeIMO - Open XML and document utilities for .NET

May 9, 2026 · View on GitHub

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

Conversion packages

Markdown and rendering packages

Reader and ingestion packages

Authoring and export packages

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

Google Workspace packages

Examples, benchmarks, and release notes

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 via QuestPDF and SkiaSharp

Excel family

OfficeIMO.Excel: workbook, worksheet, table, range, style, and reporting helpers
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 using PDF standard fonts
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 should be treated separately because QuestPDF and SkiaSharp add a larger rendering/runtime surface.

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"]
  Quest["QuestPDF"]
  Skia["SkiaSharp"]

  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 --> Quest
  WordPdf --> Skia

Excel, PowerPoint, Visio, and primitives

flowchart TB
  Excel["OfficeIMO.Excel"]
  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
  PowerPoint --> OpenXml
  Visio --> Drawing
  Visio --> Packaging

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

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

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
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
QuestPDF / SkiaSharp: Word-to-PDF conversion layer only
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.

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