Adam Retter
adam@evolvedbinary.com
XML Prague
@ University of Economics, Prague
2026-06-04
@adamretter
XQuery
and
XML Databases
MEETUP

About Me
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Director of Evolved Binary
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UK - Software, Consultancy, Training, and R&D
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Co-founder and Co-owner of eXist Solutions
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Germany - TEI Publisher software
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Software Engineer / Prolific Open Source contributor
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Elemental (NoSQL/XMLDB) - Founder
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eXist-db - 20 Years as Core contributor (last 9 as main dev.)
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RocksDB - 8 Years as RocksJava main developer
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W3C XQuery Working Group - Invited Expert
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Founder of EXQuery, and creator of RESTXQ
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Enjoys Research and Development, and Snowboarding

The Plan...
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Share Knowledge and Experiences
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Have Fun!
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Talks:
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Learning XQuery One Dish at a Time - Jennifer Ramirez-Betancur (ZBMED)
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Some Experiences Gained in XQuery - Liam Quin (Delightful Computing)
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Can it Run Doom? - Younes Bahloul (Evolved Binary)
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RumbleDB: JSONiq on Apache Iceberg - Dr. Omar Hammoud (ETH Zurich)
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The Link eXtractor, a Largish XQuery Application - Dr. Nico Verwer (Rakensi)
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Elemental in XProc / AI in Open Source? - Adam Retter (Evolved Binary)
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cityEHR in Ukraine - Prof. John Chelsom (Seven Informatics)
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Then... Open... Unconference Style Discussions and Questions
Adam Retter
adam@evolvedbinary.com
XQuery + XMLDB Meetup / XML Prague
@ University of Economics, Prague
2026-06-04
@adamretter
Elemental
in
XProc

XQuery from XProc
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XProc 3.1 Step -
p:xquery -
Source Port
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Input Sequence
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Context Item
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Default Collection
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Query Port
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The XQuery
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Parameters Option
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Includes XQuery Variable Bindings
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XML Calabash 3 XProc Engine
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Call Elemental for
p:xquery -
Support Elemental embedded in JVM with Calabash
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Support Elemental Server over HTTP from Calabash
Enhancements made to Elemental
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Deserialization of all XDM Types from HTTP (Variables)
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Set Context Item from HTTP / Embedded
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Set Default Collection from HTTP / Embedded
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New XQuery Execution API (Embedded)
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Serialization of all XDM Types to HTTP (Query results)
Elemental 7.6.0 / 6.10.0 - PR #199
Upcoming: Elemental 7.6.1 / 6.10.1 - PR #224
Enhancements made to Calabash
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Connector for Elemental Embedded in JVM
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Start/Stop Elementa as needed
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Multiple Database Instances
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Conversion to/from Saxon XDM to/from Elemental XDM
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Connector for Elemental Server over HTTP
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Multiple Remote Servers - HTTP URIs
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Conversion to/from Saxon XDM to/from Elemental HTTP XDM
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Calabash - PR #673
Adam Retter
adam@evolvedbinary.com
XQuery + XMLDB Meetup / XML Prague
@ University of Economics, Prague
2026-06-04
@adamretter
What does AI mean for Open Source?

Sneak Peek of
my Upcoming Paper
Balisage 2026 🤞
Concerns / Impacts for Open Source
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SOCIAL
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ECONOMIC
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ENVIRONMENTAL
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POLITICAL
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LEGAL
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TECHNICAL
Who owns the code generated by an AI?
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How much human creativity involved?
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May not be copyrightable by you
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May not be copyrightable by anyone
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2026 - US Supreme Court - Thaler appeal
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2026 - Allen vs. Perlmutter
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What was the AI model trained on?
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Has the AI reproduced copyrighted code (patterns)
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Your code may be contaminated / violating licenses
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2025 - Class Action - Bartz vs. Anthropic PBC - $1.5B
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2026 - US Ninth Circuit - Doe vs. GitHub
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Lawyers assume that AI code reproducing training data is a violation
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Sena Evren: Who Owns the Code Claude Wrote?
AI Cannot Rewrite/Replace Existing Code
Publishing an
AI POLICY
is Critical for an
Open Source Project
What is an AI Policy?
What should/shouldn't it say?
The bare minimum you should do today...
YOU
Clearly and Publicly Label AI Generated Code and Commits
GUIDANCE IS COMING SOON... 😉
Our AI Policy at Evolved Binary
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Applies to all of our Software Projects
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We do not Accept or Create Code from AI *
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We Cautiously use AI for:
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Conversations about different algorithms/architectures
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Refactoring our code
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An LLM is basically a big text matching engine!
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Sometimes better than Regular Expressions / Perl
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Glorified find and Replace!
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e.g. Find uses of interface
XYZwhereclose()is not called
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* Excluding our fun Doom demo: XDoom
THANK
YOU
XML Prague 2026 - XQuery and XML Databases Meetup
By Adam Retter
XML Prague 2026 - XQuery and XML Databases Meetup
XML Prague @ University of Economics, Prague 2026-06-04
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