DiffKit is an application and a framework, for comparing two tables of data, field-by-field. The tables can come from any of a number of sources, such as an RDBMS or CSV file, and DiffKit is able to mix different kinds of sources in the same diff operation. It is like the Unix diff utility, but for tables instead of lines of text. Diffs can be reported at both the row and field level, and the user can configure what to compare, how to compare it, what to ignore). DiffKit is highly customizable with respect to the sources of tabular data, the details of the comparison, and the characteristics of the output (diff report).