EvotecIT/OfficeIMO

MIT-licensed, COM-free .NET libraries for creating, reading, editing, converting, rendering, and extracting Office, PDF, email, OneNote, and text formats.

What it solves

OfficeIMO is a family of .NET libraries designed to handle Office and document formats without requiring Microsoft Office, Excel, PowerPoint, Visio, or LibreOffice to be installed. It eliminates the need for COM automation, allowing these documents to be created, edited, and converted in environments like services, containers, and build agents.

How it works

Instead of automating a desktop application, OfficeIMO uses first-party implementations of document engines. For modern formats, it leverages the Open XML SDK for package mechanics, while for others (like PDF, Markdown, and legacy binary formats), it uses its own proprietary object models. It also integrates with AngleSharp for HTML/CSS parsing and Bouncy Castle for security and PDF signatures.

Who it’s for

It is built for .NET developers who need to programmatically generate or manipulate Office documents (Word, Excel, PowerPoint, Visio) and other document types (PDF, OneNote, Markdown, RTF) in headless or server-side environments.

Highlights

  • COM-free operation: Works in services and containers without needing Office installed.
  • Broad format support: Handles .docx, .xlsx, .pptx, .vsdx, PDF, OneNote, Markdown, RTF, and legacy binary formats (.doc, .xls, .ppt).
  • High-fidelity export: Supports managed export of documents to images (PNG, JPEG, TIFF, WebP, SVG).
  • Comprehensive toolset: Includes specialized libraries for drawing, OCR hooks, and Google Workspace integration.