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OfficeIMO is a family of lightweight, cross‑platform .NET libraries that make working with Office file formats easier using the Open XML SDK — no Office/COM required.

• Word: create and edit .docx documents with a friendly API
• Excel: fast read/write helpers, tables, styles, ranges, fluent composers
• PowerPoint: build .pptx slides programmatically
• Visio: basic .vsdx diagrams

Each project ships as its own NuGet package under the MIT license.

• Word → OfficeIMO.Word/README.md
• Excel → OfficeIMO.Excel/README.md
• PowerPoint → OfficeIMO.PowerPoint/README.md
• Visio → OfficeIMO.Visio/README.md
• Converters:
  • OfficeIMO.Word.Html — HTML ↔ Word
  • OfficeIMO.Word.Markdown — Markdown ↔ Word
  • OfficeIMO.Word.Pdf — PDF export for Word

• Word, PowerPoint, Visio: netstandard2.0, net472, net8.0 (Linux/macOS: net8.0); select projects also net9.0
• Excel: netstandard2.0, net472, net48, net8.0/net9.0 (cross‑platform)

• CI (Windows/Linux/macOS): single workflow badge above
• Coverage: Codecov dashboard linked above

All OfficeIMO packages are MIT‑licensed with exception of Visio which is not yet licensed. See individual project READMEs for third‑party dependency licenses (Open XML SDK, ImageSharp, AngleSharp, QuestPDF, SkiaSharp, etc.).

Below are product‑centric graphs. Arrows point from a package to what it depends on.

flowchart TB
  WCore[OfficeIMO.Word]
  subgraph Extensions
    WHtml[OfficeIMO.Word.Html]
    WMd[OfficeIMO.Word.Markdown]
    WPdf[OfficeIMO.Word.Pdf]
  end

  %% External deps
  Angle[AngleSharp]
  AngleCss[AngleSharp.Css]
  OfficeIMO.Markdown
  Quest[QuestPDF]
  Skia[SkiaSharp]

  %% Core to extensions (install these when you need that capability)
  WCore --> WHtml
  WCore --> WMd
  WCore --> WPdf

  %% Extension uses
  WMd --> WHtml

  %% External dependencies per extension
  WHtml --> Angle
  WHtml --> AngleCss
  WMd   --> OfficeIMO.Markdown
  WPdf  --> Quest
  WPdf  --> Skia

Converters (Word.Html, Word.Markdown, Word.Pdf) are actively developed and will be released to NuGet once quality and test coverage goals are met. They ship in‑repo for early evaluation.

flowchart TD
  Xl[OfficeIMO.Excel]
  OXml[DocumentFormat.OpenXml]
  ImgSharp[SixLabors.ImageSharp]
  Fonts[SixLabors.Fonts]

  Xl --> OXml
  Xl --> ImgSharp
  Xl --> Fonts

flowchart TD
  Ppt[OfficeIMO.PowerPoint]
  OXml[DocumentFormat.OpenXml]

  Ppt --> OXml

flowchart TD
  Vsdx[OfficeIMO.Visio]
  ImgSharp[SixLabors.ImageSharp]
  Pkg[System.IO.Packaging]

  Vsdx --> ImgSharp
  Vsdx --> Pkg

• Only editing/creating Word (.docx): add OfficeIMO.Word.
• Word → PDF export: add OfficeIMO.Word + OfficeIMO.Word.Pdf (pulls QuestPDF + SkiaSharp).
• Word ↔ HTML: add OfficeIMO.Word + OfficeIMO.Word.Html (pulls AngleSharp + AngleSharp.Css).
• Word ↔ Markdown: add OfficeIMO.Word + OfficeIMO.Word.Markdown (uses OfficeIMO.Markdown and OfficeIMO.Word.Html).
• Excel read/write, tables, styles: add OfficeIMO.Excel (pulls ImageSharp + Fonts for sizing and header images).
• PowerPoint slides: add OfficeIMO.PowerPoint.
• Visio drawings: add OfficeIMO.Visio (uses ImageSharp and System.IO.Packaging).

• DocumentFormat.OpenXml: 3.3.x (constraints: [3.3.0, 4.0.0))

• SixLabors.ImageSharp: 2.1.x; SixLabors.Fonts: 1.0.x (Excel)

• AngleSharp: 1.3.x; AngleSharp.Css: 1.0.0‑beta.154 (Word.Html)

• QuestPDF: 2025.7.x; SkiaSharp: 3.119.x (Word.Pdf)

We keep package ranges conservative to avoid breaking changes; see each project’s csproj for exact ranges.

• OfficeIMO.Word, OfficeIMO.Excel, OfficeIMO.PowerPoint, OfficeIMO.Word.Html, OfficeIMO.Word.Markdown, OfficeIMO.Word.Pdf: MIT
• OfficeIMO.Visio: License TBD (not MIT yet)

Third‑party dependency licenses: see their upstream repos (Open XML SDK, SixLabors, AngleSharp, QuestPDF, SkiaSharp).

If you find this project helpful, please consider supporting its development. Your sponsorship will help the maintainers dedicate more time to maintenance and new feature development for everyone.

It takes a lot of time and effort to create and maintain this project. By becoming a sponsor, you can help ensure that it stays free and accessible to everyone who needs it.

To become a sponsor, you can choose from the following options:

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

Your sponsorship is completely optional and not required for using this project. We want this project to remain open-source and available for anyone to use for free, regardless of whether they choose to sponsor it or not.

If you work for a company that uses our .NET libraries or PowerShell modules, please consider sponsoring. Thank you for considering support!

Please consider sharing a post about OfficeIMO and the value it provides. It really does help!

See individual project READMEs for detailed capability lists and code samples.