Red Hat XML language server becomes LemMinX, bringing new release and updated VS Code XML extension

A new era has begun for Red Hat’s XML language server, which was migrated to the Eclipse Foundation under a new project name: Eclipse LemMinX (a reference to the Lemmings video game). The Eclipse LemMinX project is arguably the most feature-rich XML language server available. Its migration opens more doors for future development and utilization. In addition, shortly after its migration, the Eclipse LemMinX project and Red Hat also released updates: Eclipse LemMinX version 0.11.1 and the Red Hat VS Code XML extension.

Eclipse LemMinX version 0.11.1

Eclipse LemMinX version 0.11.1 mainly focuses on bug fixes that are outlined in the changelog here. For some history, Eclipse LemMinX started as an open source project created by Angelo ZERR in mid-2018. Angelo’s XML language server implementation was well ahead of the game in terms of features and code infrastructure. As Red Hat’s interest in an XML language server continued to grow, Red Hat joined forces with Angelo (who later officially joined Red Hat as a senior software engineer) to create the most feature-rich and easy-to-use XML language server possible.

Thanks to the XML language server’s popularity and functionality, clients like Eclipse (with Wild Web Developer), VS Code (with XML Language Support by Red Hat), and Vim/Neovim (with coc-xml) started consuming the XML language server. In addition, all LSP features (completion, validation, quick fix, etc.) provided by the XML language server are easily extensible. This helped motivate other projects to extend the LSP features, instead of implementing them themselves from scratch.

For example, there are extensions specific for Maven and Liferay. The Maven extension extends the completion feature to manage advanced dependency completion, and the Liferay extension extends the hover feature to fit specific use cases. We hope that the contribution to the Eclipse Foundation facilitates easier consumption from related projects and attracts new contributors beyond people from Red Hat.

Red Hat VS Code XML extension

In addition, we released the Red Hat VS Code XML extension (which, of course, consumes the Eclipse LemMinX XML language server to provide language features). This extension provides an excellent all-in-one package for editing XML, XSD, and DTD files in VS Code, but what makes this extension stand out is the support for XSD and DTD schema validation for XML files.

This new release also focussed on bug fixes, which are outlined in the changelog here.