a voting plugin that prints receipts for the votes would be more advanced than the 'actual' voting system used in our *cough* democracies. lol and not lol.

Here are the functionalities of my network :

profiles, groups, debates (ie. sophisticated forums, where you can comment the commentaries, and where you can choose not to sort the posts by chronological order, but by any sort of the network), opinion polls, followings, friends, discussion (the same discussion as facebook), documents sharing, and the most original part : a sophisticated system of sorts and research. Any profile or group can create its own sort, in order to class any information. For example, the voting process will be one of those sort, but you'll also be able to sort by, let's say, a sort called 'relevant information' in which there will be 'this opinion is interesting', 'i need to think about this information' and 'this information is scientificly proven'. You can choose to make this sort public or private, collaborative or not, to apply it only to paragraphs in debates or to apply it on every objects of the network : it will be extremely customizable. The research engine will remain on the sorts, and will be very efficient though. For example, you can search in the debates over ecology what have wrote the right-wing people and order the posts by the biggest number of +2 votes (indeed, the major system of vote will be a -2 -1 0 1 2 vote). When the results are displayed, you can use a sort to color the paragraphs of the texts, for example, the 'relevant information' : paragraphs in 'this opinion is interesting' would be in green, 'i need to think about it' in blue, etc.

What do you think ? How to begin ? Someone to help me in Paris or by skype ? Someone interested to get involved in the project ?

How much time would it take to an expert developer to add these plugins to elgg, do you think ?

• profiles: already available in Elgg by default,
• groups: already available in Elgg by default,
• debates: there's no built-in threaded discussion forum available yet (but it might be available in the next but one major release as I've heard). Right now there is the option to add a discussion section to each group. It's a rather simplistic "forum" that allows commenting but no threaded commenting.  There might be plugins available to add a more advanced forum section but I'm not sure (there was one for a former version of Elgg but I believe it has never been updated for Elgg 1.8). Sorting might also be already available via a 3rd party plugin (there is one with allows sorting of comments outside the discussion section of groups but I don't know if it also allows for sorting of discussion threads),
• opinion polls: there are plugins available for creating polls,
• followings / friends: by default Elgg offers "following" (like Twitter) but calls it "friending". There's a plugin available to change this to Facebook-like friending,
• discussion (the same discussion as facebook): don't know what exactly is meant by the reference to Facebook discussions and how they differ from the "debates" mentioned above but as mentioned the groups can have discussion sections,
• documents sharing: already available in Elgg by default via the files plugin,
• a sophisticated system of sorts and research: well, that's something not yet available. To be honest I couldn't follow your explanation. It sounded like "sort everything by everything and allow everything...". There is a simple site search available already. The search can also be customized to a certain extend via plugins. But I guess you would need to write a very custom plugin (or hire someone to write it for you) to really suit your needs in this aspect.

Maybe you should give Elgg a try by setting up a test installation (could also be on your local computer) to get a better impression on what Elgg already offers by default. By adding a few of the additional plugins available here on the site you might be able to achieve most of what you have in mind already but it's better to test this out on your own. For specific custom work necessary you can add a topic in the professional services group here on the site. With making such a posting you will most likely get better replies regarding costs and time necessary for coding instead of only a rough estimation.

Thank you for your precise answer iionly.

I don't want to (and I can't) pay for the plugins, I asked how much time is needed to have an estimation of the feasability.

Anyway, I still need some help, because the doc is not sufficient for I really understand how to create my own plugins.  (someone?^^)

Well, i finally found a book where i learn how to develop plugins : "Elgg 1.8 Social Networking".

Before i was completely lost (i think the doc is not sufficient). This book should be recommended on the site !