A fast highly optimized implementation of popular checksum algorithms: CRC32 CRC16 CRC16C (CRC-CCITT). The library allows to calculate checksums for files memory blocks strings blobs streaming data. It is quick flexible easy to use. It supports 3 interfaces: FastCRC API (the API can be used as is or it can be used to create wrappers for languages that can use DLL or LIB) C++ Interface (C++ wrapper classes to FastCRC API) and FastCRC Type Library (includes all declarations for accessing the functionality from programming languages that can reference a .TLB such as VB 5.0 VB 6.0 VBA etc). It allows staticdynamic linking. It has no external dependencies such as MFC DLLs COMDCOM or other component. The help file has C C++ and Visual Basic examples showing how to add checksum calculations to Windows applications quickly and easily.