The aim of this tutorial is to educate attendees on the applications of Semantic Web and Social Networking (Web 2.0) technologies in digital library systems. These technologies include metadata management, semantic search and browsing, personalized and community-aware services, and semantically empowered federations of digital libraries. The semantic digital libraries can be used in enterprise scale systems such as knowledge management systems, medical records systems, legal research systems and others will be discussed at some depth. After this tutorial, the audience will be able to start using existing semantic digital libraries and apply Semantic Web technologies to digital library systems. We will start by defining problems in the domain of semantic digital libraries and present solutions that provide building blocks for semantic digital libraries, such as WordNet, DMoz, SKOS, CIDOC-CRM, and OAI-ORE. We will then present the architecture of existing semantic digital libraries, elaborate on resource management, search and browsing features, identity management and communication interfaces. We will discuss in detail the problems and solutions for bibliographic metadata management and interoperability, followed by a presentation of semantic search and browsing solutions, and other personalized and community-aware services. We will present and discuss results of an evaluation of social and semantic information discovery technologies for digital libraries [http://library.deri.ie/resource/ARfuVUi8]. We will compare results achieved using a semantic digital library with a classic, open source library. We will show how semantic digital libraries enhance user experience in information discovery. We will analyze various user satisfaction measures gathered during the evaluation. Finally we will discuss if semantic digital library users are able to retain better the knowledge they have gained while using the system. We will discuss the future of federations of digital libraries in the context of the Semantic Web and Web 2.0 Internet. Finally we will present six initiatives that adhere to the idea of a semantic digital library: SIMILE [http://simile.mit.edu/] which leverages and extends DSpace [http://www.dspace.org/] by enhancing its support for arbitrary schemata and metadata. Corrib.org [http://www.corrib.deri.ie/], which delivers semantic-aware digital library components like JeromeDL, MarcOnt, FOAFRealm, S3B, and HyperCuP. BRICKS [http://www.brickscommunity.org/] , the largest cultural heritage project in the EU 6th framework program, which applies semantic web technology for managing metadata in a European wide digital library network. FEDORA [http://www.fedora.info/], a flexible service-oriented architecture for managing and delivering digital content Greenstone [http://www.greenstone.org/], a suite of software, which use advance technologies for building and distributing digital library collections. DELOS [http://www.delos.info/], an European Network of Excellence on Digital Libraries that contributed a number of research solutions applicable to the domain do semantic digital libraries. The tutorial will be followed by a hands-on session where participants will be able to try out existing prototypes of semantic digital libraries. We will wrap up the whole tutorial by encouraging everyone to take part in the discussion on the future of semantic digital libraries. The materials from previous editions of this tutorial are accessible at http://wiki.corrib.org/index.php/SemDL/Tutorial