Eclipse LemMinX

The  LemMinX project provides an LSP implementation for the XML language (aka XML Language Server). It can be used with any editor that supports the protocol, to offer editing support (completion, hyperlink, validation, hover, codelens, ..) for XML documents (.xml, .xsd, .xslt…), as well as schema-based (XSD and DTD) validation.

The XML Language Server is extensible via a plugin system (based on a service provider interface - SPI) to provide completion, validation, etc.