A comparison of .NET ETL libraries

ETLKit vs ETLBox

This page compares ETLBox with three open-source .NET ETL libraries you may have found while searching: ETLKit, ETL.NET, and actionETL. ETLBox is the commercial product. The others are not.

If you landed here from ETLKit, or from a list of C# ETL libraries, the question is the same: what is the difference, and which one can you run in production? Below, ETLBox is compared with each project on its own, then all four sit in one matrix.

ETLKit

The library that looks like ETLBox

ETLBox used to be MIT open source, around 2018–2020. ETLKit continues that 1.x line — previously published as EtlBox.Classic, then renamed. ETLKit states the 2.0 rename is a package and namespace change, not a redesign: the public API stays the 1.x surface. Matching class names is the leftover of a shared starting point, not six years of product work.

ETLBox

The product since 1.x

Streaming engine hardened after the closed-source cut
Thousands of automated tests
Vendor support, trial, commercial licenses
Named companies in production
Paying customers fund the next year

ETLKit

The 1.x continuation

Same generation as the old 1.x engine
Community tests, not a product test suite
Maintainer and GitHub, not a vendor
No comparable public enterprise references
Stalls when the author stops

ETL.NET

A different model, not a fork

ETL.NET never shared the ETLBox codebase. It is a Linq-style, reactive pipeline library. The maintainer has publicly asked for help with documentation and tests, and reported that unit tests were largely dropped in v2. Occasional releases do not make it a supported product.

ETLBox

A library you can buy support for

Component data-flow model teams already know
Thousands of automated tests
Docs, recipes, and a support channel
Used in production at named companies
A vendor that answers when something breaks

ETL.NET

A community experiment

Different programming model (Linq / reactive)
Author reports tests were dropped in v2
Maintainer publicly asking for contributors
Community scale, not enterprise references
Stalls if the maintainer moves on

actionETL

A stalled worker-style library

actionETL is another separate open-source .NET ETL experiment, built around workers rather than a data-flow network. The last NuGet package is from January 2024. There has been no meaningful product movement since then.

ETLBox

Still shipping

Actively maintained commercial engine
Thousands of automated tests
Trial, licenses, and vendor support
Named production customers
A roadmap funded by customers

actionETL

No longer moving

Different worker-style model
No commercial test story
Last package: January 2024
Community scale
Already stalled

All four at a glance

The same criteria, one table. Green means ETLBox covers it as a product. Red means the open-source project does not.

	ETLBox	ETLKit	ETL.NET	actionETL
Product engine	Hardened streaming data flow	Same generation as old 1.x	Linq model; tests dropped in v2	Last NuGet release in 2024
Automated tests	Thousands of tests	Community tests	Author asked for help restoring them	No commercial test story
Vendor support	Support, trial, licenses	Maintainer / community	Maintainer asking for contributors	Effectively stalled
Production proof	Banks, energy, healthcare, manufacturing	No comparable public references	Community scale	Community scale
If the author stops	Customers fund ongoing development	The project stalls	The project stalls	Already stalled

Used in production — not as a weekend project

Commonwealth Bank of Australia, Deloitte, Health Catalyst, SEW Eurodrive, Calpine, FASTEC: these are not GitHub stars. They run ETLBox because a nightly load cannot depend on a maintainer’s spare time. That is what a commercial license actually buys — a library that already survived production.

Evaluate ETLBox

Try the commercial library, not the 1.x lookalike

If the API looks familiar, that is expected — ETLKit froze the old surface. A trial key unlocks the product that was built after that. NuGet without a key is limited to 5,000 rows per data flow.

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