RightField is an open-source tool for adding ontology term selection to Excel spreadsheets. RightField is used by a ‘Template Creator’ to create semantically aware Excel spreadsheet templates. The Excel templates are then reused by Scientists to collect and annotate their data; without any need to understand, or even be aware of, RightField or the ontologies used. RightField is a standalone Java application which uses Apache-POI for interacting with Microsoft documents. It enables users to import Excel spreadsheets, or generate new ones from scratch. For the scientist, the main advantages of RightField are that it enables them to consistently annotate their data without the need to explore and understand the numerous standards and ontologies available to them, and it does not require them to change normal practice. Everything is embedded in the Excel spreadsheet. To find out more about using RightField,  see the RightField user guide and see examples of RightField-enabled spreadsheet templates.