xslt

Nokogiri (鋸) makes it easy and painless to work with XML and HTML from Ruby.

http://defiantjs.com

koalixcrm is an Open Source Python CRM and ERP based on django

This is the official Symphony CMS repository.

The low-code Knowledge Graph application platform. Apache license.

Stroom is a highly scalable data storage, processing and analysis platform.

eXist Native XML Database and Application Platform

DITA Open Toolkit — the open-source publishing engine for content authored in the Darwin Information Typing Architecture.

Make Your RSS Beautiful!

ArchivesSpace, the archives management tool

Temario y ejercicios de Desarrollo de Aplicaciones Multiplataforma (DAM)

XML without worries

Справочник XSLT и XPath

Quba is a viewer for electronic invoices

Generic Linked Data browser and UX component framework. Apache license.

An XSLT-based Schematron processor.

Java Schematron library that supports XSLT and native application

A number of small tools for generating and manipulating diagrams, mostly based around Graphviz

Ballerina xslt module

A Swift package for working with HTML, XML, and other markup languages, based on libxml2.