Microsoft's sudden deprecation of Polyglot Notebooks leaves users fuming

Microsoft has deprecated Polyglot Notebooks, an extension for Visual Studio Code (VS Code) which supports multiple languages in one Jupyter Notebook, including C#. It was the main use for .NET Interactive, a project whose future must now also be in doubt.

Microsoft’s Claudia Regio, from the Platform and Tools team, made the deprecation announcement on GitHub yesterday, giving just over one month’s notice, with deprecation set for March 27th.

 The extension will remain installed, she said, but "bug fixes and support will end immediately" and "issues in this repository related to the Polyglot Notebooks extension will be closed as not planned," as will issues "related to using .NET Interactive as a kernel in other Jupyter frontends." 

"This is a disaster for us. We use polyglot Notebooks for All our data science courses. All the people saying do not trust or rely on Microsoft were sadly right again," remarked a user on Reddit.

The deprecation has surfaced another long-standing issue, which is that Azure Data Studio (ADS), a fork of VS Code specifically for working with SQL databases, is set for retirement at the end of this month. The main replacement for ADS is meant to be the SQL Server extension for VS Code, but Polyglot Notebooks were documented as the recommended replacement for data analysts, as opposed to developers or DBAs (database administrators).

"Given today’s announcement … what is the official guidance from Microsoft regarding a replacement for the T-SQL + markdown notebook functionality that existed in Azure Data Studio?" asked another user, with the official response from Microsoft technical writer Randolph West being that "there is no guidance at this time."

West added a frank comment, stating that "I’m just as big a fan of Azure Data Studio as you are," but that "as a result of the deprecation announcement for Polyglot Notebooks, I am legally bound to remove that recommendation.”

Regio recommended using C# file-based apps, a feature of .NET 10 that enables a C# file to be run without setting up a project, as a replacement; but although useful for learning C#, this feature is not close to an equivalent.

Both ADSS and Polyglot Notebooks were well liked by users. Users raised an issue asking for the retirement of ADS to be reconsidered, with comments such as "Azure Data Studio is a beautiful, user-friendly experience. Trying to achieve the same thing in VS Code is incredibly clunky." The Polyglot Notebooks extension has over 1.8 million installs and a four star rating in the VS Code marketplace, unlike the SQL Server extension which has recent comments such as "riddled with bugs … how is a tool that worked fine (ADS) being discontinued and this is being recommended as the alternative?"

"While Polyglot Notebooks may be deprecated, our mission to make C# development delightful and accessible continues in our flagship products; we're carrying that work forward through C# Dev Kit and the next generation of AI-powered coding experiences," wrote Regio.

Users will be hard to convince. "Polyglot notebooks are incredibly useful for prototyping stuff and demoing. Almost hard to believe that something so unique and useful is getting killed off like that," said another comment.