There's a unique feature of wikisource: anyone can contribute, even if he
doesn't know at all the language of the text that it is editing (it is sufficient to recognize the characters of that language). It would be a little bit painful, but I could proofread an hungarian text, finding and fixing some scannos. A small contribute, but a valuable one. On the contrary, I can't contribute at all to any other hungarian project.
I could too apply some basic formatting to the same, incomprehensible hungarian text, but only using standard wiki markup, or css/html, that are universal languages. I could do most of needed work using shared templates and scripts, without any knowledge of the hungarian language.
This uniqueness of wikisource (only shared by images and other media into Commons) has been underestimated IMHO.
Alex