Wanted: XML Technology Reviews

• a dynamically extensible xml scripting language, written in c. has a stand-alone mode and an apache mode, just like php.exe and mod_php.
• GPL license, however extension modules are dynamically loaded, and there is no restriction on what license these modules can be developed under, including proprietary licenses.
• virgule.sourceforge.net and sourceforge.net/projects/virgule

xvl - derived from mod_virgule, which runs the advogato site, has turned into an actual scripting language in order to provide sufficient non-hard-coded functionality for web site designers.

xvl is designed to be extensible, and therefore able to leverage existing XML technologies (if written in c), such as xslt (through DV's excellent project, libxslt).

issues, dev status, roadmap

xvl's origins, from mod_virgule, are unconventional. a site *must* be managed - including all subdirectories and authentication - via mod_virgule. this is somewhat unsatisfactory. i will be morphing the code and the example site into a more 'conventional' system by creating mod_xvl, and then mod_auth_xvl.

in this way, it will be possible [via mod_xvl] to mix xvl and php, html etc etc in the way that apache developers expect, and also apache developers will also be able [via mod_auth_xvl] to leverage Trust Metric-based authentication from php and other scripting languages.

lkcl

• pyxml - a python xml library
• A package collecting the tools required for writing basic XML applications in Python, along with documentation and sample code. Features include (but are not limited to) SAX, DOM, the xmlproc validating parser, an Expat interface, and more.
• http://sourceforge.net/projects/pyxml
• Python License

comments, anyone?

• python xmllib that comes with the standard python distribution
• Python License
• http://python.org

• XML/HTML toolkit, written in C, developped within the Gnome project
• Dual licenced LGPL or W3C IPR (MIT like)
• http://xmlsoft.org/
• longuer description at the given page, quickly it supports: XML, XML DTD validation, HTML, DocBook SGML (hack specific parser) SAX, DOM like, tree manipulations, XPath, XPointer, XInclude URI handling, FTP and HTTP clients, customizable I/O layer, Support for SGML catalogs (XML Catalogs coming), or a pluggable catalog API.
• advogato is based on libxml2, used by gdome (DOM2 library), and libxslt (XSLT library), etc.

• XSLT toolkit, written in C, developped within the Gnome project
• Dual licenced LGPL or IPR (W3C IPR based MIT like)
• http://xmlsoft.org/XSLT/
• implementation of the XSLT transformation language, relatively fast, but not yet at 1.0
• KDE and Gnome are starting using it to render on-the-fly the docbook XML documentation to HTML pages. Embedded in AXKit now.

it's just impossible to list here, even the rance of open sources ones is huge from expat to xml.apache.org, AXKit, 4Suite, IBM tools, Saxon, XSV, etc ...

no it's really impossible to list everything, there is a number of XML software catalogs, like http://www.xmlsoftware.com/ (seems down today) and http://www.garshol.priv.no/download/xmltools/ to list just 2 of them.

A Freshmeat search for "XML" turns up 400 hits. Random sampling seems to indicate that at least one in three of these are primarily XML projects (as opposed to other projects that happen to use XML in some peripheral way); that's still over 100 XML projects.

There are lots of other XML-specific software directories out there; some are more focused on free software, others on commercial vendors. I presume you're looking for something more -- intelligent filtering? discussion? -- but your proposed tabular results and the listings so far don't offer anything beyond what Freshmeat and the rest have.

StAX is a small extension to the SAX2 APIs. Like SAX, it allows you to write efficient (memory and performance) handlers for XML documents. However, rather that writing a single, monolithic, ContentHandler object, any sub-tree of the XML document can be delegated to another handler. This makes it easier to write modular, extensible, XML applications. One typical pattern is to write a separate handler for each datatype in your schema.

An adaptor allows StAX handlers to be used with an SAX2-compliant XML parser.

Language: Java (concept could be easily re-implemented in many other languages).

Licence: LGPL

Availability: StAX currently lives in the CVS tree of the BioJava project (although there are no problems compiling it standalone -- drop me a mail if you want a copy). This is largely historical accident. I'm planning to separate it out this weekend, and it will then move to http://stax.sourceforge.net/.

hi there egnor, well, you kindly supplied some info that will make advogato, and this article, useful and to the point: you provided a reference to a search engine [i keep forgetting about freshmeat :)]. so yes, you posted in the right place, and i appreciate v. much you doing so.

AxKit is an XML Application Server for Apache, for both dynamic and static content. It implements server-side transformation of XML content, allowing you to deliver the same content in different formats, such as HTML, WML, PDF, etc. Everything in AxKit is a plugin, so we implement different language transformation modules loaded at runtime, such as XSLT (based on Gnome libxslt or Sablotron), XPathScript, or XSP.

XSP is the technology that implements the dynamic side of things. It is a language implemented by Cocoon originally. XSP to the user is a bit like Cold Fusion, in that you have tags that implement functionality. However unlike CF, XSP is pure XML. Developers can implement their own tags for XSP by just writing a Perl class, and adding some boiler-plate code, and a tag specification (much like writing a Perl class that uses Exporter). This is much easier than both the JSP2 and Cocoon XSP way of writing tags libraries.

A couple of confusions I have wanted to clear up for a while about AxKit, and here seems like a good place:

• AxKit is (or should be) Cocoon implemented in C. A lot of the core parts of AxKit are implemented in C. The XSLT transformation is in C. There are only a few small Perl bits in each request (except XSP, which is byte-compiled to Perl bytecode before execution).
• AxKit is not like the Cocoon 1 model at all, it is much more like the Cocoon 2 model of execution - a falsehood I've seen bandied about on the Cocoon-Users list. That is to clarify, AxKit users describe how their XML is to be processed using Apache configuration directives that they add to their httpd.conf or .htaccess files. They can use xml-stylesheet processing instructions, just as Cocoon 1 uses, but only as an override for the main mechanism described here.

Language: C and Perl (with a gradual port of more code to C as time permits). Also quite tied to Apache right now.

License: Dual licensed under the GPL and Artistic License.

Other: AxKit is developed commercially for free by AxKit.com, where we build content management and other types of solutions around the platform. We welcome other interest in our services.

[this message kindly written by matt s. and posted here on his behalf]

Use it and never have to write HTML again. :)

Are you looking for stuff for working with XML generally or applications using specific XML dialects?

The DSML Tools are an XML-using application I wrote; manipulation of directory data in a XML form. It's written in Java, and based on Apache Xerces, the Netscape LDAP SDK and various other bits and pieces. License is GPL/MPL dual.

Gerv

well, personally, i'm looking for mature-enough, or standards-based c-based technologies / libraries that i can plug in to xvl and make a shameless plug for xvl (which is going really well: mod_auth_xvl and mod_access_xvl were about an hour's work each! :) and friends at the same time. and libxslt fit _that_ bill incredibly well. however, i realise that c is not everyone's favourite, so thought it best to open up the article. egnor is spot-on, though: whilst a reference article is good, intelligent discussion is better. if i get time to do some research into egnor's and daniel's excellent recommendations, i'll post references to those xml-techs that i think are worthwhile, even if this article drops off the front-page :)

Qt 3.0 (beta 1 available here) includes the QXml module - I haven't used it much yet, but so far, it seems quite nice and complete.

Supports SAX2 and DOM Level 2. Pretty good docs included in the tarball.

Licenses: GPL or QPL, license for developing proprietary software available for a fee

Language: C++

The GNU ClasspathX project includes basic XML processing support. It supports SAX2, DOM Level2, an XML Pipeline framework (with streaming validator -- there's some cool SAX2 support there), utilities (SAX2 DOM parser, XMLWriter), and now JAXP 1.1 support. For the moment you need to build "gnujaxp.jar" from CVS; there's no formal "release" yet.

It's all under the GPL, "with library exception".

When last I measured: Smaller (lots!) and faster (2x?) than Xerces. And something I found curious: the Xerces v2 internal architecture is really similar to this, except that the XML Pipeline framework uses only SAX2 and predates that IBM work by well over a year. Go figure.

This is the current version of Ælfred2; older versions (buggier, non-GPL) are bundled with a variety of projects (the Saxon XSLT engine, and the DOM4j work).

For some reasom my HTML didn't go through, the URL for Entity is http://www.entity.cx