Developed by zxing,zbar
Zxing and Zbar are both open-source to scan barcodes or 2-D "graphical barcodes" and retrieve the data encoded.
Zxing
ZXing refer to short for Zebra Crossing. It is implement in the Barcode Scanner (application) that is an Android app.You can visit the website of Barcode Scanner or download the project from Google