Syncro Soft
Syncro Soft is a privately held software company founded in 1998 with a large area of expertise in XML technologies: XML Schema, Relax NG, Schematron, XSLT, XPath and XQuery. The main product Oxygen XML Editor provides the best coverage of the today XML technologies; it complies with the established standards released by W3C and other organizations and enhances developer productivity through an intuitive and innovative XML IDE. Syncro Soft is a member of the W3C. Another product developed by Syncro Soft is Syncro SVN Client (a Subversion client).
xml-buddy.com
Clemens Uhlenhut trading as xml-buddy.com was established in 2010 to develop and market software for XML and JSON. Their tools are being constantly improved based on customer feedback and in-house implementations. They use mature, open-source libraries to keep their tools compliant to XML and JSON standards and compatible with existing workflows.
Wintellect
Wintellect is a consulting, debugging and training firm dedicated to helping companies build better software, faster. They are Microsoft's largest developer training vendor. Wintellect's offerings include full lifecycle application development, architecture, analysis and design services, UI/UX design, project management, debugging and performance tuning, database design and development, as well as in-depth, multi-day .NET on-site and open enrollment training.