In 2010 we released the NILDE software version 4.0, introducing many innovative features for libraries and end-users. Thanks to the widespread participation in improving the new system, many enhancements have been made during these last 12 months since the software was first launched. Librarians have to face several new challenges in Interlibrary Loan, such as sharing of electronic resources, licensing, and International ILL. In this paper we present the new concepts introduced in the NILDE system and which may contribute to shape a different and more effective way of resource sharing among Italian libraries, including: - The catalogs where libraries expose their holdings: NILDE offers the possibility to link to any union or national catalog to which a library belongs, that can be now searched via Z39.50 and library holdings retrieved in MARC21 and XML format. Print, electronic and consortial holdings are managed. - The ranking of lending libraries: the new rank algorithm suggests the most suitable library to which a request be sent, based on the principle of maintaining the system in equilibrium between borrowing and lending requests. - The multilingual user-interface: the NILDE user-interface has been redesigned and is provided currently in Italian, English and French. These features make NILDE a suitable system to help librarians to face the new challenges, to support other library networks around the world and to support International ILL.