1. Introduction
2. LI as Text Categorization
2.1 Previous Surveys
3. A Brief History of LI
4. On Notation
4.1 An Archetypal Language Identifier
4.2 On the Equivalence of Methods
5. Features
6. Methods
7. Empirical Evaluation
7.1 Standardized Evaluation for LI
7.2 Corpora Used for LI Evaluation
7.3 LI Shared Tasks
8. Application Areas
9. Off-the-Shelf Language Identifiers
10. Research Directions and Open Issues in LI
11. Conclusions