XsltDb is a browser-based application development environment for DotNetNuke. It offers smooth coding (syntax highlighting, code completion, context help), database access (SQL, portal data isolation, dedicated portal database), AJAX, XSLT.
XAMP is framework for fast and pretty web-development. It's MVC compliant: xml (M), xslt (V) and php (C). The main point of XAMP is coding by XML-tags. XAMP syntax is very compact and simple, but powerful and flexible.