Internal links:

- Latest release: download – documentation – bugs – changes.
- Gforge: information to use the anonymous access to the Subversion repository.
- Sample: to start with the MPFR library.
- FAQ: frequently asked questions.
- Credit: involved projects and developers.
- History: links to all MPFR versions and past events.
- Algorithms: documents describing algorithms used in MPFR.
- MPFR in the world: publications citing MPFR and various links about MPFR.
- How to contribute to MPFR.

External links on MPFR:

- Try MPFR online, thanks to Tomonori Kouya.
- Mailing-list for announces (moderated).
- Mailing-list for users and developers (Gmane mirror).

The MPFR library is a C library for
multiple-precision floating-point computations with *correct rounding*.
MPFR has continuously been supported by the
INRIA and the current main
authors come from the
Caramel
and AriC project-teams at
Loria
(Nancy, France) and
LIP
(Lyon, France) respectively; see more on the
credit page.
MPFR is based on the
GMP
multiple-precision library.

The main goal of MPFR is to provide a library for multiple-precision floating-point computation which is both efficient and has a well-defined semantics. It copies the good ideas from the ANSI/IEEE-754 standard for double-precision floating-point arithmetic (53-bit significand).

MPFR is free. It is distributed under the GNU Lesser General Public License (GNU Lesser GPL), version 3 or later (2.1 or later for MPFR versions until 2.4.x). The library has been registered in France by the Agence de Protection des Programmes under the number IDDN FR 001 120020 00 R P 2000 000 10800, on 15 March 2000. This license guarantees your freedom to share and change MPFR, to make sure MPFR is free for all its users. Unlike the ordinary General Public License, the Lesser GPL enables developers of non-free programs to use MPFR in their programs. If you have written a new function for MPFR or improved an existing one, please share your work!

- The following C++ interfaces for MPFR,
*very different*in their design (and in particular, in the strategies for intermediate precisions, so that they can yield different results), are available:- MPFRCPP, written by Alexey V. Beshenov. This interface uses a modern C++ design with using of classes, templates and function objects.
- Another MPFR C++ wrapper, written by Pavel Holoborodko. The precision of the temporary results in an expression is chosen as the maximum precision of its arguments, and the final result is rounded to the precision of the target variable.
- The
`mpfr::real`class, written by Christian Schneider.It consists of a template class with precision and rounding mode passed as template arguments. Hence, effectively a new type will be created for each precision and rounding that is used. All the operators available for fundamental floating point types as well as type conversions from and to other types, and the set of mathematical functions known from

`math.h/cmath`are implemented. This should allow for an easy substitution of, e.g., a double with the wrapper class in most cases. - MPFR++, developed in the AriC project. Warning! The version currently available (2004-02-27) is not up-to-date, is not compatible with the latest releases of MPFR and has several bugs. News from 2007-05-02: Changes have been done on this interface since, but they are not published yet.
- The gmpfrxx C++ interface for both GMP and MPFR, written by Jon Wilkening.
- Boost also includes an interface for MPFR, as part of its Multiprecision library.

- The multiple-precision arithmetic is very useful for interval arithmetic. Get a multiple-precision interval arithmetic library MPFI, based on MPFR. This library MPFI is developed by Nathalie Revol from the AriC project and Fabrice Rouillier. MPFI implements a subset of the mathematical functions provided by MPFR. Read more explanations on Nathalie Revol's software page.
- The GNU MPC library, a library for multiple-precision complex arithmetic with correct rounding, based on the MPFR and GMP libraries.
- The Perl interface Math::MPFR.
- The Python interface bigfloat (documentation), written by Mark Dickinson.
- The Python bindings for GMP, MPFR and MPC (gmpy2).
- A LISP interface, written by Richard Fateman. This package also contains a FFT implementation.
- The functional programming language Ursala includes an MPFR interface.
- Haskell binding to MPFR (hmpfr), written by Aleš Bizjak.
- Ruby bindings for GMP and MPFR.
- Eiffel interface to MPFR.
- The RandomLib MPFR interface (C++ classes).
- R interface to MPFR.
- Ada bindings to GMP and MPFR, written by Vincent Diemunsch (announce in the MPFR mailing-list).
- The Racket language includes an MPFR interface.
- Java bindings to MPFR.

- The KDE calculator Abakus by Michael Pyne (supporting arbitrary precision thanks to MPFR as of version 0.90).
- The ALGLIB.NET project implements multiple-precision linear algebra using MPFR.
- The APRON library, dedicated to the static analysis of the numerical variables of a program by Abstract Interpretation.
- The ARAnyM virtual machine as of version 0.9.12, for the FPU emulation.
- Arb, a C library for arbitrary-precision floating-point ball arithmetic, developed by Fredrik Johansson.
- The numerical analysis library BNCpack can be compiled with MPFR.
- CGAL (Computational Geometry Algorithms Library).
- Eigen, a C++ template library for linear algebra, via Pavel Holoborodko's MPFR C++ wrapper.
- FLINT (Fast Library for Number Theory).
- MPFR is also used by the Fluctuat tool developed and used internally at the CEA (France).
- FractalNow, a fractal generator.
- Gappa, a tool intended to help verifying and formally proving properties on numerical programs, by Guillaume Melquiond.
- GCC: first in GFortran, then in the middle-end phase as of GCC 4.3, to resolve math functions with constant arguments. More information.
- Genius Math Tool and the GEL language, by Jiri Lebl.
- Giac/Xcas, a free computer algebra system, by Bernard Parisse.
- GNU Awk, as of version 4.1.0 (for optional arbitrary-precision arithmetic).
- The iRRAM - Exact Arithmetic in C++ implementation from Norbert Müller (University of Trier, Germany).
- The Julia language implementation (source).
- The C++ continued fractions toolkit libcff (no longer maintained), by Johan Vervloet.
- Macaulay 2, a software system devoted to supporting research in algebraic geometry and commutative algebra (as of version 1.1).
- The Magma computational algebra system.
- The Maple computer algebra system via the RS library, since version 11 (reference).
- Mathemagix, a free computer algebra system, in the numerix package.
- MCAS/libivl (computational algebra and plot system / interval computations library), by Mateusz Paprocki.
- MPACK (multiple precision arithmetic BLAS and LAPACK), by Nakata Maho, supports MPFR as of version 0.6.5 (2010-05-21).
- The MPFRCX library for the arithmetic of univariate polynomials over arbitrary precision real (MPFR) or complex (MPC) numbers, without control on the rounding.
- The mpfs library, an experiment in stochastic lazy floating-point arithmetic, from Keith Briggs.
- Multiprecision Computing Toolbox for MATLAB.
- NARS2000, an experimental APL interpreter, has datatypes for multiple-precision floating-point numbers via MPFR.
- Protea, a software devoted to protein-coding sequences identification, by Arnaud Fontaine and Hélène Touzet.
- The Rasqal
RDF Query
Library optionally uses MPFR for
accurate
`xsd:decimal`implementation. - ReactOS Calc uses MPFR when multiple-precision support is enabled.
- MPFR is one of the components of SAGE.
- Soft84, a calculator for Android devices.
- Sollya, a tool environment for safe floating-point code development, written by Christoph Lauter and Sylvain Chevillard (in the old Arénaire project).
- SXEmacs can be compiled with MPFR support (as of version 22.1.3).
- SweeD, a tool that implements a composite likelihood ratio test for detecting selective sweeps.
- TRIP, a general computer algebra system dedicated to celestial mechanics.
- The Wcalc calculator by Kyle Wheeler (supporting arbitrary precision thanks to MPFR as of version 2.0).

- MAPM, a portable arbitrary precision math library in C, by Michael C. Ring.
- CoStLy, a Complex interval Standard functions Library developed by Markus Neher (Karlsruhe).
- The XSC-Languages, FI_LIB, FILIB++ and intpak software developed at University of Wuppertal (Germany).
- The CORE library: a library for robust numerical and geometric computation.
- The CLN C++ library (GPL).
- The Quad-Double package by David Bailey, Yozo Hida and Sherry Li.
- The numerical difference utility from Nelson Beebe, similar to diff but for numerical files.
- The mpmath Python library for arbitrary-precision floating-point arithmetic.
- The Constructive Reals Calculator from Hans Boehm.
- The xrc - exact reals in C from Keith Briggs.
- The precise computation software from Oliver Aberth.
- The
`RR`

class from NTL, which implements asmooth extension

of IEEE floating point to arbitrary precision and guarantees a platform-independent behaviour. - A continued-fraction package based on GMP, by François Balsalobre.
- SCSLib, a fast and lightweight multiple-precision library supporting the four arithmetic operations, developed in the old Arénaire project; the precision (210 bits by default) is fixed at compile time. CRlibm, a correctly rounded elementary function library.
- Sun's libmcr, a correctly rounded library of basic double-precision transcendental elementary functions.
- The PreciseFloating (floating-point arithmetic library) project in Java, by Daniel Aioanei: directed rounding, rational arithmetic and arbitrary precision arithmetic based on regular continued fraction expansions.
- The decNumber package by Mike Cowlishaw (IBM): arbitrary-precision decimal arithmetic.
- The Intel® Decimal Floating-Point Math Library for the IEEE 754-2008 Standard (download).
- The calc calculator by Landon Curt Noll. This calculator implements a rational arithmetic, with a fallback to some kind of multiple-precision fixed-point arithmetic (integer multiplied by a configurable epsilon).
- The Qalculate calculator by Niklas Knutsson, based on CLN.
- The MathCW mathematical function library (supporting binary and decimal floating-point arithmetic) by Nelson H. F. Beebe.
- Libraries for extended precision on GPU: gnuprec.
- The mpdecimal package for correctly rounded arbitrary-precision decimal floating-point arithmetic, by Stefan Krah.

- The C standard: the N1256 draft (C99 with TC3) and the C99 rationale (especially Section 7.12 and Annex F). New in C99. The N1570 draft (last C1x draft of C11).
- LIA stuff. These standards are freely available.
- The General Decimal Arithmetic pages from Mike Cowlishaw.
- The Digital Library of Mathematical Functions project, whose aim is to develop an electronic version of the Handbook of Mathematical Functions from Abramowitz and Stegun.
- The Computer Arithmetic & Numerical Techniques (CANT) research group at University of Antwerp, Belgium.
- The Table Maker's Dilemma page from the AriC (formerly Arénaire) project at ENS-Lyon, France.
- Mathematical constants and computation by Xavier Gourdon and Pascal Sebah.
- The 754R standard revision group.
- The CerPAN ANR project.
- The EVA-Flo ANR project.
- LOCOMAT (the Loria Collection of Mathematical Tables).