Free & Open Source Code Editor

Microsoft's vscode source code is open source (MIT-licensed), but the product available for download (Visual Studio Code) is licensed under this not-FLOSS license and contains telemetry/tracking. According to this comment from a Visual Studio Code maintainer:

When we [Microsoft] build Visual Studio Code, we do exactly this. We clone the vscode repository, we lay down a customized product.json that has Microsoft specific functionality (telemetry, gallery, logo, etc.), and then produce a build that we release under our license.

When you clone and build from the vscode repo, none of these endpoints are configured in the default product.json. Therefore, you generate a “clean” build, without the Microsoft customizations, which is by default licensed under the MIT license

The VSCodium project exists so that you don't have to download+build from source. This project includes special build scripts that clone Microsoft's vscode repo, apply patches, run the build commands, and upload the resulting binaries for you to GitHub releases. These binaries are licensed under the MIT license. Telemetry is disabled.

If you want to build from source yourself, head over to Microsoft’s vscode repo and follow their instructions. VSCodium exists to make it easier to get the latest version of MIT-licensed Visual Studio Code.