deka provides decimal floating point arithmetic. It is based on mpdecimal, the C library used to provide support for the Decimal module in Python 3. You will need to install mpdecimal to use deka; otherwise your executables will not link. It is available at http://www.bytereef.org/mpdecimal/ mpdecimal has also been packaged for some Linux distributions, such as Debian (libmpdec-dev - available in Jessie and later) and Arch (mpdecimal). mpdecimal, in turn, implements the General Decimal Arithmetic Specification, which is available at http://speleotrove.com/decimal/ For more on deka, please see the Github home page at https://github.com/massysett/deka Tests are packaged separately in the deka-tests package.