6.5 Future Developments
Of all the W3C specifications relevant to XML linking, XPointer is the standard that has progressed most slowly. There are several reasons. One is that adoption of XPointer has been very slow, and at the time of writing there is only one implementation available. This is not suScient to act as a catalyst for the W3C standardization process to continue. Some implementors are concerned that XPointer is too complex (in particular, its concept of ranges) and that this keeps vendors from supporting it. There have also been attempts to create profiles of XPointer (which exclude ranges and are therefore much easier to implement); but this would significantly reduce the functionality supported by the core standard, and so far the W3C working group has not agreed to this plan. Unfortunately, XPointer is one of the essential building blocks of the XML linking framework; but as long as the W3C standardization process remains stalled, there will be either little or no progress or some vendors will introduce proprietary solutions to the problem of addressing subresources.
Apart from these more political issues, XPointer is already becoming somewhat outdated by the continuing development of the standards on which it is basedmost particularly, XPath. While XPointer is built on top of XPath 1.0, XPath 2.0 [Berglund+ 01], described in section 5.6, is already under development, and it is very possible that it will reach recommendation status earlier than XPointer. Because of the problems with XPointer standardization, currently no attempts are being made to base XPointer on XPath 2.0.
It is our opinion that it is often better to have a mediocre standard than no standard at all. While XPath and XSLT have demonstrated that even non-perfect standards can provide many benefits (and the opportunity to improve them with their next release), XPointer's development is an example of how the lack of standardization of an essential component of a bigger framework (the XML linking technologies) can stall the development of a very interesting and promising set of technologies and applications.