Endangered languages are linguistic varieties for which intergenerational transmission has become threatened or interrupted under contact pressure from more dominant languages. Massive language obsolescence, more acute than biodiversity loss, is part of intangible cultural heritage loss and is often seen as a violation of linguistic human rights and a threat to ethnic and national identities. Additionally, indigenous minority languages and cultures accumulate many phenomena which are rare from the point of view of world's dominant languages and research paradigms. Three main types of proactive responses to language loss include language documentation, language support, and targeted language policy and planning, although a “benign neglect” or even active repressive measures are still an issue for many endangered varieties. Due to the pro-active efforts in the past 30 years, work with endangered languages is now a broad vibrant field familiar to legislators, media, and the general public, although this varies across different places. The role of language archives has increased, but endangered languages and dialects are covered by documentation and support to a variable extent, and archives are not always easily accessible to communities. There is a constant search for a balance between the stakeholders (native speakers, new speakers, activists, researchers, and legislators), and this affects the prestige of languages and the motivation of speakers to preserve them. Yet, language documentation has been becoming more community-oriented, and many new speakers have emerged due to effective language support. Some revitalization methods are more effective, while others are superficial and rather lead to the exoticization and “folklorization” of endangered languages. Many minority varieties still face serious challenges: further expansion of dominant languages, economic globalization, increased migration, climate change, a need for digitization, which calls for better co-ordination of efforts to support them.