Go to standardXSLT function: object system-property (string)
Standard excerpt:
The argument must evaluate to a string that is a QName. The QName is expanded into a name using the namespace declarations
in scope for the expression. The system-property function returns an object representing the value of the system property
identified by the name. If there is no such system property, the empty string should be returned. Implementations must provide
the following system properties, which are all in the XSLT namespace: xsl:version, a number giving the version of XSLT implemented
by the processor; for XSLT processors implementing the version of XSLT specified by this document, this is the number 1.0,
xsl:vendor, a string identifying the vendor of the XSLT processor, xsl:vendor-url, a string containing a URL identifying the
vendor of the XSLT processor; typically this is the host page (home page) of the vendor's Web site.
Examples (xslt:xml): Overview
66:2
Interactive xlab: [xsl:value-of] [xsl:template]