1) Leightweight = small file size is, if not anyone else's, my definition... So, what is right definition ?
If I were to make an MU option available with future versions, I would not restrict it to coming only as a 'fork'; I would make it an optional sNews package... in other words have both the Single User and Multiple User packages available for all future versions... though I don't know how practical that would be.
2) Which would bring a lot, do it not... I mean every addon/MOD made for each should be made for the other (give or take specific things) for instance...
1) I don't know what the 'right' definition is for lightweight and I'm not so sure that there is one, as it relates to code.
There will always be different interpretations though.
2) Our current way of making mods & addons available is to leave it up to individual users to do the 'making' and share their work voluntarily.
We don't have an "Official Mods & Addons List", like the more popular CMS dev sites do.
We don't formally promote any specific mod or addon as a "Dudes Choice", and we don't limit what gets posted.
Some mods can be equally applied to both SU and MU (1.6) while others need additional work in MU... depends on the mod.
Each version of sNews could be issued with 2 engine files... snewssu.php (for single-user) and snewsmu.php (for multi-user) with both being compatible with the rest of the package files. We would need to list the database table data and instructions for both in the readme.html file. The downloader would then make the decision on which engine file to install with the rest of the file-set based on which one is needed.