SgmlReader is a .NET library that is handy for converting SGML content (like HTML and OFX) into well formed XML via XmlReader, XmlDocument, XDocument or XPathDocument. It runs on Windows and Linux using .NET core.
A sanitizer to remove elements and attributes from SGML based text files, such as HTML and XML. Note that this is a very simple implementation, but by using whitelists and a naïve URL detection implementation XSS may be prevented. Use at your own risk though.