[tannhaeuser]

XPath/XSLT 2+ also have only a single implementation (by the spec author) so don't meet W3C's requirement of two interoperating implementations. Basically, XSLT ceased to be a "standard" whereas XSLT 1.0 had excellent portability across libxslt, Saxon, Xalan, and MS' xslt.exe.

Edit: there is/was a token implementation for XSLT 2.0 called Gestalt

[now]

It also worth noting that the specification’s author also built his company on this single implementation.

[zmix]

> XPath/XSLT 2+ also have only a single implementation

As far as XPath goes, that's wrong:

1. Saxon (the one you talk about)

2. BaseX (an XQuery 3.1 processor)

3. Xidel (implements many XQuery 3.1 features)

4. eXistdb

5. fonto-xpath (NodeJS)

6. frameless.io (JS, also XSL)

And these are the ones, which face the public internet. I think, Microsoft has an 2.x implementation, I am pretty sure, IBM and Oracle do so, as well.

Now, as for XSL-T, you are right: the easily available implementations are Saxon, but, as it seems, also frameless.io (which I just found out about a few minutes ago, so I may be wrong). But again, I guess, that big enterprise has their own solutions bundled.

[orf]

Saxon supports all xpath versions though? It also bundles some very dangerous functions, some of which xcat can take advantage of.