In the 2021 Developers Survey, Visual Studio Code continues to be ranked #1, with 70% of the 82,000 respondents using it. post 
In 2011, Microsoft made a high-profile hire. Former IBMer and technical lead on Eclipse Java development tools, Erich Gamma, joined the company to work on an unspecified project. Microsoft officials said he'd open a lab in Zurich, Switzerland. And that's about all they revealed. post
Gamma hit the "open-source button" for VS Code's GitHub repository on stage at a Microsoft conference in 2015 as part of his demonstration of the editor's broad extension support. To make the point clear, he demonstrated VS Code with the then Microsoft-maintained Go extension. post
The idea behind the Language Server Protocol (LSP) is to standardize the protocol for how such servers and development tools communicate. This way, a single Language Server can be re-used in multiple development tools, which in turn can support multiple languages with minimal effort. site
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Vague memory has Erich spending some time at Taligent where committed himself to ui modules. wikipedia
RedMonk says,code editors are up for grabs. post