Serbert is a command line utility which performs a Bit Error Rate Test (BERT) on serial lines for Unix and it's variants. It does this by transmitting bytes, and waiting for their uncorrupted return.
Serbert, however, does not provide a true Bit Error Rate Test (BERT), as it does not check the individual bits returned. It uses the operating systems standard serial interface, which provides the status of each returned byte.
The current version of Serbert is 0.3.0, and can be obtained here.
This project is hosted by Sourceforge.