This book constitutes the refereed post-workshop proceedings of the Second International Workshop on Worldwide Language Service Infrastructure, WLSI 2015, held in Kyoto, Japan, in January 2015. The 4 full papers included in this volume and presented together with 2 short papers and 8 invited papers, were carefully reviewed and selected from 7 submissions. The papers are categorized into four parts: introducing metadata and annotations; providing technologies for language service platforms; atomic language services across different interfaces, policies, and development of language resources and services; and collecting reports on language service application.