The Cm software implements the construction of ring class fields of imaginary quadratic number fields and of elliptic curves with complex multiplication via floating point approximations. It consists of libraries that can be called from within a C program and of executable command line applications. For the implemented algorithms, see A. Enge, The complexity of class polynomial computation via floating point approximations, Mathematics of Computation 78 (266), 2009, pp. 1089–1107.

The software is written by Andreas Enge and is distributed under the Gnu General Public License, either version 3 of the licence, or (at your option) any later version (GPLv3+).


Version 0.3 "Wurstebrei", released in March 2016, comes with the following new features:


Version 0.2.1 "Blindhühnchen", released in March 2015, comes with the following new features:

Version 0.2, released in February 2012, comes with the following new features:

The initial release of version 0.1 "Apfelkraut" was made in November 2009.