Devs Sound Alarm After Microsoft Subtracts C/C++ Extension From VS Code Forks

Some developers are 'crying foul' after Microsoft's C/C++ extension for Visual Studio Code stopped working with VS Code derivatives like VS Codium and Cursor, reports The Register. The move has prompted Cursor to transition to open-source alternatives, while some developers are calling for a regulatory investigation into Microsoft's alleged anti-competitive behavior. From the report: In early April, programmers using VS Codium, an open-source fork of Microsoft's MIT-licensed VS Code, and Cursor, a commercial AI code assistant built from the VS Code codebase, noticed that the C/C++ extension stopped working. The extension adds C/C++ language support, such as Intellisense code completion and debugging, to VS Code. The removal of these capabilities from competing tools breaks developer workflows, hobbles the editor, and arguably hinders competition. The breaking change appears to have occurred with the release of v1.24.5 on April 3, 2025.

Following the April update, attempts to install the C/C++ extension outside of VS Code generate this error message: 'The C/C++ extension may be used only with Microsoft Visual Studio, Visual Studio for Mac, Visual Studio Code, Azure DevOps, Team Foundation Server, and successor Microsoft products and services to develop and test your applications.' Microsoft has forbidden the use of its extensions outside of its own software products since at least September 2020, when the current licensing terms were published. But it hasn't enforced those terms in its C/C++ extension with an environment check in its binaries until now.

Developers discussing the issue in Cursor's GitHub repo have noted that Microsoft recently rolled out a competing AI software agent capability, dubbed Agent Mode, within its Copilot software. One such developer who contacted us anonymously told The Register they sent a letter about the situation to the US Federal Trade Commission, asking them to probe Microsoft for unfair competition -- alleging self-preferencing, bundling Copilot without a removal option, and blocking rivals like Cursor to lock users into its AI ecosystem.

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