From its very beginning, the potential of extracting valuable knowledge from the Web has been quite evident. Web mining, i.e. the application of data mining techniques to extract knowledge from Web content, structure, and usage, is the collection of technologies to fulfill this potential. Interest in Web mining has grown rapidly in its short history, both in the research and practitioner communities. This paper provides a brief overview of the accomplishments of the field, both in terms of technologies and applications, and outlines key future research directions.