EC publishes open source code…

EC publishes open source code of legislation editor

Published on: 07/07/2015
Last update: 31/10/2017

The European Commission is about to make available as open source a prototype of LEOS, a software solution for drafting and automatic processing of legal texts. The software currently supports legal texts issued by the EC, yet can be extended to support other legislative processes.

Legislation Editing Open Software or LEOS was announced on on Joinup, the European Commission’s collaboration platform for ICT solutions, on 22 June. Development of the prototype is financed by the European Commission’s ISA Programme, which is also responsible for Joinup.

LEOS will be published using the European Union’s public software licence, EUPL. The code will be available shortly.

The LEOS prototype uses templates to help users draft EC directives. Using drag and drop, users can create chapters, sections and other document divisions. A WYSIWYG editor lets users create fine-grained document elements such as paragraphs, subsections and points. Using an approach similar to revision control, the tool lets users compare versions of documents. LEOS also makes it possible for several users to edit the same simultaneously. The prototype lets users export their texts to HTML and PDF.

The LEOS prototype stores all text, modifications and other document related data in an XML format, Akoma Ntoso V2 . This open standard is the precursor of the OASIS standard LegalDocML. “It makes sense to switch to LegalDocML”, says Geraud Berton, LEOS project manager at the European Commission. “But we first need to understand better the various levels of compliance.”

Writing, not amending

The LEOS project aims to reduce the time involved in creating and adapting laws and regulations, the ISA Programme explains. “Drafting new legislation is a complex process, involving many actors. In most democratic countries, there are three phases in the process: the preparatory phase, the adoption phase, and the entry into force. The objective of this action is to make this time-consuming process with its increasingly pan-European dimension more efficient.”

ISA’s LEOS project began in 2011 with an inventory of legislative text tools in use at European Institutions and the EU Member States, national parliaments and publication offices. The project also identified best practices and determined if existing tools could be reused. One of such tools is AT4AM, software for authoring and management of amendments on parliamentary texts used by the European Parliament. The EP published AT4AM in 2013, also using the EUPL.

AT4AM is for amendments and LEOS is for drafting legal texts, says project manager Berton. The output of LEOS is a single XML file, and depending on the workflow, AT4AM will create separate files for each amendment. The two will work together, engineer Berton says: “A file drafted with LEOS could be amended using AT4AM.”


More information:

LEOS on Joinup


Fri, 17/07/2015 - 19:03

"Open source" and "access denied" on the same page. Please fix that..

MathiasSchindler (not verified)
Mon, 20/07/2015 - 13:53

The link to results in an "access denied" response.

Sat, 25/07/2015 - 19:51

Hi, the link is still in an 'access denied" unfortunately, any fix ?

Mon, 27/07/2015 - 09:00

The Leos project page has meanwhile been updated and is now publicly readable.

Peter Ruzicka (not verified)
Thu, 26/10/2017 - 08:32

Is this project still alive?
Latest source commits are from 2013. LEOS declares incubator phase prototype. At4amos commits 2013 too, no package to easily start it. Can you provide link with latest information?
Thank you

Tue, 31/10/2017 - 09:31

You can try to contact the teams involved:


for AT4AM:


Hope this helps,