BilAudio-7 system is implemented in C++. Graphical user interfaces are created with open source, cross-platform C++ GUI library wxWidgets. wxWidgets media player (wxWidgets) and FFMPEG are used for audio handling. The Audio Annotation Tool uses MPEG-7 Feature Extraction library that we adapted from the MPEG-7 XM Reference Software. XML data is handled with open source Xerces-C++ XML Parser library. Finally, Tamino is used as the XML-native database to store the MPEG-7 XML descriptions of audios. The system can use any XML database that supports XQuery.