Barcode1D is a pure Ruby gem for handling many kinds of 1-dimensional barcodes. Implemented are Code 128, Code 3 of 9, Code 93, Code 11, Codabar, Interleaved 2 of 5, COOP 2 of 5, Matrix 2 of 5, Industrial 2 of 5, IATA 2 of 5, PostNet, Plessey, MSI (Modified Plessey), EAN-13, EAN-8, UPC-A, UPC-E, UPC Supplemental 2, and UPC Supplemental 5. Patterns are created in either a simple format of bars and spaces or as a run-length encoded string. This only generates and decodes the patterns; actual display or reading from a device must be implemented by the programmer.