The Vector .dbc file format is a proprietary format used for their CAN tools. A number of other CAN tool vendors also use it. Vector offers a library to read/write the format. Btw, Kvaser has a free editor for download.
I'd much rather work in a saner format like JSON or XML. CANard uses JSON. Kayak has it's own format. Busmaster (Bosch/ETAS) is free and uses it's own format. There is a GitHub project called canmatrix that converts between the different formats.
Has Carloop settled on a format yet? I would go with JSON as we can find lots of open source software to support it.