Researchers often need to share documents with their colleagues or with research project partners. Their main requirements are : sharing a bibliographic database with PDF documents with a group of 2 to 30 persons and more, a free web interface ( in a secure computer environment if possible) , easy import/export formats (Bibtex, RIS, Zotero...) allowing them to go on using their own bibliographic software. We present the different tools studied with their advantages and limits regarding the ideal solution.