This section of the documentation provides information about Saxon licensing, including required notices for open-source components that have been incorporated into Saxon, and acknowledgments of contributors.

This documentation relates both to the open source Saxon-HE product and to the commercial products Saxon-PE and Saxon-EE. The conditions of use are of course different in the two cases; there are also differences in the third-party components that are included.

The information in this section applies to both the Java and .NET versions of Saxon, unless otherwise specified.

The source code of Saxon can be considered for licensing purposes as having four parts:


The open-source Saxon-HE product is made available under the Mozilla Public License (the "License"). Prior to Saxon 9.5 MPL Version 1.0 was used; from 9.5 onwards, MPL Version 2.0 is used. You may not use the software except as permitted by the License. You may obtain a copy of the License at

MPL version 2.0 allows software to be declared as "compatible with secondary licenses". Saxon code, in general, is NOT compatible with secondary licenses. This means it is not possible to redistribute the source code under a different license. The reason for this is the difficulty of obtaining the consent of all past contributors to the code.

Saxon-HE is built from code in categories A, B, and C above. This code is published and is available for use under the terms of the license. Most users will never need access to source code, but for those who do, it is published in two forms:

Saxonica does not actively solicit contributions to the code from external developers. We will accept contributions only if the requirements and design have been agreed in advance, if comprehensive test material is supplied in a suitable form, and if a contribution agreement is signed.

Saxon-HE includes a separate JAR file, saxon9-xqj.jar, which contains Saxon's support for the XQJ interface, a standard API for access to XQuery engines from Java. In previous Saxon releases this was made available as part of the main JAR file. It has been decoupled because it has been pointed out that the license under which Oracle distributes XQJ is not a pure open source license under the definition used by the Open Source Initiative: specifically, it does not allow modifications, and it does not allow redistribution except as part of a product that satisfies all the compatibility tests. Saxon satisfies these conditions, but some users are only prepared to use code that conforms to OSI-approved licenses. If you fall into this category, please delete the saxon9-xqj.jar file. (In Saxon-PE and Saxon-EE, the XQJ components are delivered as part of the main Saxon JAR file.)

Saxon-EE and Saxon-PE

The Enterprise and Professional editions of Saxon are commercial products released under the terms and conditions published at

These products include some open source components. In particular, they include the open-source components used to build Saxon-HE (categories A, B, and C above) in their entirety; they also include some open-source components (notably the ASM and ICU libraries) which are not used in Saxon-HE. Although your contract with Saxonica is entirely defined by the commercial license, the existence of an open source license for these components gives you additional rights, which are described above.

The Saxon SQL extension

The Saxon SQL extension is available as an open-source plug-in to Saxon-PE or Saxon-EE (on the Java platform only, not available on the .NET platform). It will not run with Saxon-HE because it relies on XSLT element extensibility, a feature not available in Saxon-HE. However, the code of the SQL extension itself is open-source and is issued under the Mozilla Public License, meaning that you are free to extend it and customize it to your needs, even though it requires Saxon-PE or Saxon-EE to run.

EXSLT extensions

A substantial number of extension functions defined in EXSLT are available as an open-source plug-in to Saxon-PE or Saxon-EE. Many of these are implemented as reflexive extension functions, and therefore rely on a mechanism not available in Saxon-HE. However, the code of the these extension functions itself is open-source and is issued under the Mozilla Public License 2.0, meaning that you are free to extend it and customize it to your needs, even though it requires Saxon-PE or Saxon-EE to run. (See EXSLT extensions for more information on the functions available.)

Note: this does not apply to implementations of the EXPath extension functions, which since Saxon 9.6 are implemented in code that is Saxonica-proprietary. (See EXPath extensions for more information on the functions available.)


Redistribution of Saxon-HE is freely permitted under the terms of the Mozilla Public License 2.0. Note that this requires inclusion of all the necessary notices. If any source code changes are made, the license requires that they be published (or at any rate, made available to your users); but you are not required to publish the source of your own application code if it is in separate modules.

If you produce a product that includes or requires Saxon-HE, please refer to it prominently as "The Saxon XSLT and XQuery Processor from Saxonica Limited", and include the URL of the home page, which is at As a courtesy, please take reasonable steps to ensure that your users know that they are running Saxon.

Redistribution of Saxon-PE or Saxon-EE as a component of a commercial application is possible under commercial terms; prices are published in the Saxonica online store, and a specimen contract will be supplied on request.

Technical Support (Saxon-HE)

Software distributed under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the specific language governing rights and limitations under the License.

There is no guarantee of technical support, though we are usually able to answer enquiries within a few days. Please use the bug trackers and support forums provided on the community site at There is also a mailing list available at Please check the bug tracker at for details of known errors; all bugs are listed there, whether they apply to the open-source or commercial versions of Saxon.

Unless otherwise stated, any code snippets that are published on a public forum in the course of a request for technical support are considered to be implicitly licensed for use in Saxonica's test suite, or where relevant for inclusion in the product itself, for release under the Mozilla Public License.