Massive Multi-User Virtual Environments (MUVEs) like Second Life, enabling userbasedcontent creation in a 3D-space and real-time online interaction via avatarmovements, gestures, multi-user chat and object exchange, currently go through a rapidboost of usage-rates. Possibilities for using 3D virtual worlds for learning and teachingpurposes are immense as they enable to set up online learning based on all didacticaland methodological approaches used in traditional and distance learning settings andallow to implement multiple combinations of approaches within one single platform.Existing educational projects in Second Life are mainly single-organization-centred andthere is a general lack of structured support for practitioners, especially concerningmodels for learning scenarios. LLL3D project plans (A) to develop, implement and testlearning scenarios for five different target groups within the field of Lifelong Learning byanalyzing case studies of best practice, developing scenario models structured in atarget group- and methodology-related grid, and implementing a LLL3D project space inSecond Life ("European Lifelong Learning Island"), (B) to establish a community ofresearchers, teachers and practitioners interested in using MUVEs in Lifelong Learningand to link existing communities from different target groups, and (C) to promote,disseminate, rise awareness and increase acceptance for educational use of MUVEsamong researchers, trainers, practitioners and multipliers in Europe. The main outputsof LLL3D are (1) A structured grid of learning scenarios and best practice cases for theuse of MUVEs for Lifelong Learning ordered by target groups and methodologiesaddressed, (2) A Second Life project space with implementations of the scenariosdeveloped and in-world links to best practices analyzed, and (3) a community ofpractitioners, researchers, teachers and students linking different target groups inLifelong Learning and being connected via different in- and out-world communicationareas and facilities. Thus, LLL3D has general impact on improvement of support forEuropean practitioners, beginners and multipliers in the field of Lifelong Learningregarding the use of MUVEs in research and practice, on production of synergeticeffects through linking of different learning communities and target groups andovercoming single-person and single-institutional approaches, on the establishment of aEuropean research and practice area in Lifelong Learning, on the linking of differenttarget groups in Lifelong Learning in Europe and on general awareness rising,promotion, dissemination and increase of acceptance for MUVEs as a highly promisingcutting-edge technology for distance learning.