This book constitutes the thoroughly refereed proceedings of the Second International Workshop on Trustworthy Eternal Systems via Evolving Software, Data and Knowledge, EternalS, held in Montpellier, France, in August 2012 and co-located with the 20th European Conference on Artificial Intelligence (ECAI 2012). The 10 revised full papers presented were carefully reviewed and selected from various submissions. The papers are organized into three main sections: natural language processing (NLP) for software systems, machine learning for software systems, roadmap for future research.