Posit, a public benefit corporation whose best-known product is RStudio, has released a public preview of Positron, based on the same open-source core as Visual Studio Code, but as a next generation data science IDE for R and Python.

Although R and Python are the initially supported languages, there are plans to support other languages in future. Developers have already put in a request for Julia, also popular for data science work. The IDE is based on Code-OSS, the open source project which also forms the basis of Visual Studio Code, and this can be confusing since there is syntax highlighting for languages including Julia, but no support for it as an interpreter for Positron.

According to the FAQ the reason for forking Code-OSS rather than just creating extensions for VS Code are because “our aspirations go far beyond what is possible via just extensions … VS Code’s extension API doesn’t give us enough leverage to modify the main workbench surface.”

This is a similar rationale to that given by the Eclipse Foundation for creating the Theia IDE, which is also based on Code – OSS. However, the Positron project will suffer from the same limitation, that it must use the Open VSX Registry for extensions rather than the better-supported Visual Studio Marketplace.

That said, Open VSX is better than starting from scratch, and means a generous range of extensions is already available for Positron, including one for Quarto, an open source technical publishing system which uses Jupyter notebooks or plain text markdown.

Why is Posit creating a new IDE and what will happen to RStudio? One reason is that the popularity of VS Code means that there is a level of investment in Code-OSS that is hard to achieve independently. The company also notes that “Positron runs the interpreter separately from the IDE, so unlike in RStudio a crash in R or Python will not crash the IDE.”

The FAQ also states though that “some R-focused features will remain exclusive to RStudio” and that “we are committed to maintaining and updating RStudio.” 

Currently Positron is described as an “early stage project” so RStudio remains the primary product for now. Sustaining two IDEs equally long-term is challenging though, so it is likely that one or the other will become the primary focus for Posit.

Positron is open source on GitHub but is licensed under the controversial source-available Elastic License 2.0. The company states that “this restriction is necessary for us to build a sustainable business around Positron while also offering it free of charge to the community.” The restrictions though may limit community enthusiasm for contributing to the project. 

The RStudio IDE by contrast is licensed under AGPL (GNU Affero General Public License) v3 for the free community edition, and the proprietary Posit License Agreement for the Pro version.