The mpc library, developed by A. Enge in collaboration with P. Zimmermann, implements the basic operations on complex numbers in arbitrary precision, which can be tuned to the bit. This library is based on the multiprecision libraries gmp and mpfr . Each operation has a precise semantics, in such a way that the results do not depend on the underlying architecture. Several rounding modes are available. This software, licensed under the GNU Lesser General Public License (LGPL), can be downloaded freely from the URL
The latest version 0.4.5 has been released in December 2005. This library is used in our team to build curves with complex multiplication, and is de facto incorporated in the ECPP program.
We plan to make A. Enge's program that builds elliptic curves with complex multiplication available. This program is a very important building block for cryptographic purposes as well as for primality proving (fastECPP).