OpenRefine is a powerful tool for working with messy data, originally released as "Freebase Gridworks" and later acquired by Google. It bills itself as a simple, yet effective solution for cleaning up and normalizing data, making it easy to find typos, variations in phrases, formatting errors, and other issues that can be difficult to spot in large datasets. With OpenRefine, users can clean up and reformat data, identify patterns and relationships, and even categorize data automatically using custom text facets. The tool is designed for bulk operations and can handle a variety of file formats, including CSV, XLS, and JSON. It also includes features such as undo/redo functionality, detailed activity logs, and the ability to use records and rows separately to organize data. OpenRefine can be used to clean up data from various sources, including app exports, old spreadsheets, and email lists, making it a valuable tool for anyone working with messy or outdated data.