# Excel-DNA/ExcelDna

Excel-DNA - Free and easy .NET for Excel. This repository contains the core Excel-DNA library.

Repository: https://github.com/Excel-DNA/ExcelDna
Canonical: https://ross.abutalabs.com/products/exceldna
Homepage: https://excel-dna.net
Language: C#
License: Zlib
License Family: permissive
Topics: excel, hacktoberfest
Last push: 2026-08-23T11:04:31+00:00

## Health v2 (maintenance only)
Score: 73/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 24, longevity 100
- inputs: {"age_days": 4964, "days_push": 10, "days_rel": 299, "gap_med": null, "n_releases_24m": 1}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1496, forks 293 (observed 2026-08-28T04:04:53.633726+00:00)

## What it is
Excel-DNA is an open-source .NET library that integrates .NET code into Microsoft Excel via .xll add-ins. It lets developers write high-performance user-defined functions, macros, ribbon customizations, and task panes in C#, VB.NET, or F#.

## Use cases
- create excel user-defined functions in c#
- build an excel add-in with .NET
- migrate VBA macros to .NET
- add custom ribbon tabs to excel
- write high-performance worksheet functions
- package a standalone .xll excel add-in
- call .NET code from excel formulas

## When to choose
- you want to extend Excel with .NET languages instead of VBA or C/C++ XLLs
- you need high-performance UDFs with multi-threaded recalculation support
- you want a free, permissively licensed (Zlib) library for commercial Excel add-ins
- you need to support a wide range of Excel versions from a single add-in

## When to avoid
- you need cross-platform Excel automation outside Windows
- you are building web-based or Office.js add-ins for Excel Online
- your project is not .NET-based

## Facets
- artifact type: library
- maturity: stable
- function: sdk, plugin-system, developer-tools
- domain: developer-tools
- platform: windows, dotnet
- tags: excel-addins, udf, xll, ribbon, interop, csharp, fsharp, vbnet, automation, excel

## Member repositories
- Excel-DNA/ExcelDna (main) score 73

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:53.633726+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T04:33:11.205197+00:00, confidence not recorded.
  - readme: https://github.com/Excel-DNA/ExcelDna (fetched 2026-08-28T04:04:53.633726+00:00, sha 55359b3b937c)
  - homepage: https://excel-dna.net (fetched 2026-08-29T11:38:27.924186+00:00, sha 17c576d7ebfa)
  - site_page: https://excel-dna.net/docs/introduction (fetched 2026-08-29T11:38:27.956177+00:00, sha 01e2ce2f0b60)
  - site_page: https://excel-dna.net/docs/category/guides---basic (fetched 2026-08-29T11:38:28.030620+00:00, sha 637b34015be2)
  - site_page: https://excel-dna.net/docs/category/guides---advanced (fetched 2026-08-29T11:38:28.068179+00:00, sha 6d5756973435)
- Data as of 2026-08-30T08:39:29.467469+00:00.