From a single source I want to be able to generate different output PDFs, only changing a few switches :

• slides deck
• a manual document
• source files for examples

The slides may contain notes.

Here’s an archive that contains an example document and complementary files. See this documentation document for more details (itself maintained with such an .org source).

Here are my slides :

An in PDF.

Thanks to the Hupstream staff and other participants of Distro Recipes for the interesting discussions and contacts. Looking forward to participating to the next edition.

Note that I’ve pasted in wordpress the HTML generated by org-mode, so I hope it isn’t broken too much.

My typical use case is a french lecture on Python where the text is written in french, as well as some of the code comments and examples

We’ll use org-mode’s babel module to include and manage the Python
examples. The goal is to write the source of the Python programs
directly in the same org source as the class book’s text, and to extract them into a subdir (with the “tangle” feature), so that they can be shipped to the students to experiment with.

The minted LaTeX environment is used, for babel, to make the Python syntax highlighting.

#+LANGUAGE:  fr
#+LaTeX_HEADER: \usepackage[latin1]{inputenc}
#+LaTeX_HEADER: \usepackage[french]{babel}
#+LaTeX_HEADER: \usepackage{color}\usepackage{minted}

# Local Variables:
# coding: latin-1
# org-src-preserve-indentation: true
# tab-width: 4
# End:

#+LATEX_HEADER: \makeatletter
#+LATEX_HEADER: \renewcommand\minted@pygmentize[2][\jobname.pyg]{
#+LATEX_HEADER:   \def\minted@cmd{pygmentize -l #2 -f latex -F tokenmerge
#+LATEX_HEADER:     \minted@opt{gobble} \minted@opt{texcl} \minted@opt{mathescape}
#+LATEX_HEADER:     \minted@opt{startinline} \minted@opt{funcnamehighlighting}
#+LATEX_HEADER:     \minted@opt{linenos} -P "verboptions=\minted@opt{extra}"
#+LATEX_HEADER:     -O encoding=UTF-8,outencoding=iso-8859-1 -o \jobname.out.pyg #1}
#+LATEX_HEADER:   \immediate\write18{\minted@cmd}
#+LATEX_HEADER:   % For debugging, uncomment:
#+LATEX_HEADER:   %\immediate\typeout{\minted@cmd}
#+LATEX_HEADER:   \ifthenelse{\equal{\minted@opt@bgcolor}{}}
#+LATEX_HEADER:    {}
#+LATEX_HEADER:    {\begin{minted@colorbg}{\minted@opt@bgcolor}}
#+LATEX_HEADER:   \input{\jobname.out.pyg}
#+LATEX_HEADER:   \ifthenelse{\equal{\minted@opt@bgcolor}{}}
#+LATEX_HEADER:    {}
#+LATEX_HEADER:    {\end{minted@colorbg}}
#+LATEX_HEADER:   \DeleteFile{\jobname.out.pyg}}
#+LATEX_HEADER: \makeatother

$ python
Python 2.7.3 (default, Jan  2 2013, 16:53:07) 
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> print "Hello, world!"
Hello, world!
>>>

#+name: helloworld
#+ BEGIN_src python :tangle examples/helloworld.py :noweb yes \\
:shebang #!/usr/bin/python :padline no :exports none
# -*- coding: utf-8 -*-

# Ceci est un exemple d'affichage d'une chaîne accentuée

name = raw_input("Quel est vôtre nom ? ")

print "J'espère que ça va bien aujourd'hui", name
#+ END_src

$ python examples/helloworld.py 
Quel est vôtre nom ? François
J'espère que ça va bien aujourd'hui, cher François

# +BEGIN_latex
\inputminted{python}{examples/helloworld.py}
# +END_latex

# -*- coding: utf-8 -*-

# Ceci est un exemple d'affichage d'une chaîne accentuée

name = raw_input("Quel est vôtre nom ? ")

print "J'espère que ça va bien aujourd'hui, cher", name

Elle portera à la fois sur l’économie du logiciel libre et sur l’essort d’OpenStack dans le cloud.

N’hésitez pas à venir nombreux sur le campus pour écouter les interventions de Jonathan Le Lous, Julien Brichard et Raphaël Ferreira, et rencontrer votre serviteur

Plus de détails sur le site de Minet.

Note that you may need to adjust the MySQL table creation templates if you’re running librdf version 1.0.16 (see this bug for details).

The first example will load data from a file, and store the parsed model to the RDBMS, while the second example, will reload the model and issue queries on it.

These examples don’t do much, but hopefully, they’ll help you get started if you’re interested in using redland/librdf.

One potential benefit can be interoperability with other languages like PHP, for instance if you’re running harvesters in Python that will save facts in a triple store, which is then accessed by a PHP application that will publish a Web interface.

Unfortunately, the default PHP bindings are not really object-oriented, so the code isn’t looking so good.

But thanks to a gentleman named David Shea, there is an object-oriented library named LibRDF (case is sensitive), that helps write nice looking PHP.

I discovered it via the blog post of Felix Ostrowski, who took over the maintenance of the LibRDF library (still the docs live on the original author’s site).

In his post, Felix illustrates how you may use it to parse Richard Cyganiak’s FOAF profile.

But the examples he gives don’t illustrate the full potential of persistence of the RDF graph into the DB.

Here’s my contribution in 2 examples that will hopefully help : first, one that load Richard’s FOAF to the DB, and one, that later retrieve the saved model and perform the same query (both pushed to my github clone of the library).

There may be some problems with the use of librdf, including its availability, as it is not full PHP of course… and I’ve heard of memory management problems, but, depening on your needs, this may be quite handy for writing Linked Data applications.

Alongside HTML pages for humans, and the RDF/XML that had already been added to it this means that a new flavour of RDF is now available.

The Turtle format offers the benefits of both machine-readable meta-data, and a somehow human readable textual format too.

For instance, you may check the apache2 Turtle meta-data from the command-line with :
$ curl -L -s -H "Accept: text/turtle" http://packages.qa.debian.org/apache2

Here’s a link to a colorized HTML preview of http://packages.qa.debian.org/a/apache2.ttl.

Under the hood, the XSLT stylesheets of the PTS have been reworked to produce the Turtle format by default, and later convert them to RDF/XML.

Every Debian source package then has a reference URI in the Linked Data word, in the form http://packages.qa.debian.org/PACKAGE_NAME, that redirects, through proper content-negociation (the HTTP Accept header) to the HTML, RDF/XML or Turtle documents. For apache2, these are, resp. at http://packages.qa.debian.org/a/apache2.html, http://packages.qa.debian.org/a/apache2.rdf and http://packages.qa.debian.org/a/apache2.ttl.

The meta-data uses the model of the ADMS.SW ontology (1.0), and the content has also been slightly updated to make it more conformant to the ADMS.SW specifications (checks done with the ADMS.SW validator).

Let’s hope this makes RDF more familiar to Debian folks, and allows more Linked Data interlinking with other resources about FLOSS packages.

Finding none that would be suitable (i.e. including graphical examples and not only being the canvas for a workshop), I tried to proceed with making one of my own.

I’ve reused the document git concepts simplified, whose content seemed quite good, and have converted it to a set of slides.

Here’s the result, which has been reworked a bit vs. the original “git concepts simplified” :

Here’s the PDF version.

Note that if you prefer a version that aligns more with the original, here’s also an older version, in : https://github.com/olberger/git-notes/tree/master/gcs

Update: For the lone reader that cannot attend my presentation, I should recommend to read first the HTML version by Sitaram at git concepts simplified, as the slides miss some details (which I’ve kept in the beamer notes only), then only refer to my slides in a second time, for some additions.

If you want the org-mode source (containing the dot source of the diagrams), contact me. I’ll maybe upload the source into some Git repo whan I have enough demand/time

Here are my slides :

Also available here as PDF.

From now on, the Debian Package Tracking System (PTS) will produce, alongside HTML pages meant for humans, RDF pages meant for Linked Data / Semantic Web aware applications.

Every Debian source package, which used to have an HTML page like http://packages.qa.debian.org/packagename now has a corresponding RDF/XML document available provided that the application/rdf+xml content-type is required (the HTTP client being redirected to the proper HTML or RDF document).

The main objective is to try and produce (closest as possible from the source, at debian.org) an authoritative description of Debian’s packages in an interoperable format (RDF using the ADMS.SW 1.0 ontology).

Thus, each package in Debian can be identified on the Semantic Web with a unique URI like http://packages.qa.debian.org/apache2, which is dereferenceable as RDF.

Here’s a graph representing the resources included in http://packages.qa.debian.org/apache2 (click on the image to load it) :

You can see an example of such an RDF representation for the apache2 source package in trying (with the ‘raptor2-utils’ package installed):

$ rapper -o turtle http://packages.qa.debian.org/apache2


If you prefer more visual/navigatable versions, use one of the Linked Data browsers referenced in wikipedia or see the output of the W3C RDF validator.

For more details about the underlying format see a raw RDF/XML dump :

$ curl -L -v -H 'Accept: application/rdf+xml' http://packages.qa.debian.org/apache2


Any Semantic Web application can then reference that resource, which becomes part of the Linked Open Data cloud.

There are probably lots of uses that could emerge from this, but the immediate I can think of is the matching of Debian packages with other packages/projects (upstream, downstream, other dists) in an interoperable way (see other projects like distromatch, etc.). At the moment, the doap:homepage of the upstream SoftwareProject resources generated by the PTS can be such a simple matching key (it’s actually much more complex than that, but will be the topic of further efforts).

AFAICT, this is the first large deployment of an ADMS.SW 1.0 implementation. On my machine, I’ve counted almost 1.5 million triples generated.

Stay tuned for more installments on similar topics.