Mozilla just approved Meta-Press.es v1.0 in addons.mozilla.org. It’s now possible to install this add-on in Firefox, in a few clicks.
This release includes the following improvements over the initially published proof of concept :
It supports the selection of which newspapers to search in, via filters, that are saved in the Firefox add-on storage between two usages ;
It supports exporting and importing results (or selection of results) via a .JSON file ;
It supports exporting results (or selection) in RSS or ATOM ;
It supports 50 sources, 10% of them brought by contributors ;
It supports defining new sources from the setting panel.
So I covered the points : 2. ; 3. ; 4. ; ½ 5. ; ½ 6 plus the issues listed in the introduction of my previous roadmap and the promises of my excerpt are now met.
In the future, we might focus on growing the source base : 200, 2000, 20 000 ? Let’s discover how many sources can be defined with the current system, with instant tag filtering as it feels now.
The checking suite to maintain all those sources (my point 1. in the previous roadmap) would already be useful with 50 sources  and will become the mandatory next thing to implement.
To finish, if a broad audience comes to this work, internationalisation (i18n) of the add-on would become an interesting feature, even if it’s already possible to search in some french newspapers, and virtually possible to define newspapers from every language, using month_nb to convert dates.