In this paper we present requirements, trends, models and proposed methods relating to the issue of providing libraries with sustainable, technological sup-port, both in terms of economic sustainability and in terms of successful adap-tation to the continuously evolving user needs and environment. Tangible benefits, but also limitations, regarding established trends such as open source software, appropriate to library needs are highlighted while new application and service delivery models, such as Software as a Service (SaaS), virtualiza-tion and/or Cloud Computing are presented, in relationship with practical issues libraries are facing.