As is the case with many of the standards that are used today, there is a relatively confusing history that lies behind the XSL and XSLT standards. While it is true that many XSL editors also serve as XSLT editors, the reverse is not always the case, due to the difference between these standards.

Originally, XSL was intended to work as a combination of XML and XSL commands that could be used to generate a variety of different types of information. The W3C proposal for XSL featured these two things as separate parts of the overhead protocol. By using high level XML descriptions of the page information and layout, the transformation commands could be used to transform the XML into whatever output format was desired, be it a different kind of XML formatting or even an HTML page output. This provides users with the maximum amount of flexibility, as they can produce a variety of different output formats using the same type of commands. This means that XSL editors can be used to produce a variety of different outputs, using the same commands and XML data.

However, this was seen by Microsoft as providing more flexibility than was needed and becoming overly complicated. Since the majority of users would output HTML documents, Microsoft saw the inclusion of the XML formatting section of XSL as being excessively complex. As a result, Microsoft took the transformation part of the XSL protocol that W3C had created and used that as its core specification. While this takes out some of the flexibility that the XSL standard had introduced, it also provided ease of use for anyone who was using the protocol for outputting HTML documents.

This decision by Microsoft led to the split between XSL and XSLT. XSL is the specification that describes the formatting objects that are to be used. This is also informally known as the XSLFO or XSL-FO. The transformation part of the specification became known as XSLT, which is the part used to transform XML data into various types of objects. Primarily, this is the type which is used by the most people today, due to the fact that the formatting objects are not necessary.

As a result, XSLT editors can provide a user with the ability to transform XML documents into various forms, without the requirement that they use the XSLFO formatting objects. While this reduces some of the advantage of the overall protocol, the ease of use is seen by many to be well worth the reduction.

Some of the early Microsoft XSLT editors were less than satisfactory when it came to functionality. However, as the protocol has evolved and implementation of it has advanced, there have come into existence a variety of different XSL editors and XSLT editors that provide all the functionality that could ever be asked of the protocol. For anyone seeking to learn more in-depth information about these specifications and their associated editors, the W3C site features a variety of information concerning the protocol specifications, as well as the history of the protocol.