The Diofant project is a fork of the SymPy, started by Sergey B Kirpichev, last regular SymPy’s commit is cbdd072, (22 Feb 2015). The git history goes back to 2007, when development was in svn.

The project was named after the Diophantus of Alexandria. His “Arithmetica” is one of the earliest known texts that use symbols in equations. “Diofant” is a transliteration of Диофант, from Russian.

Unless stated otherwise, all files in the Diofant project are licensed using the new BSD license:

Copyright (c) 2006-2018 SymPy Development Team
Copyright (c) 2013-2018 Sergey B Kirpichev

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

a. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
b. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
c. Neither the name of the copyright holder nor the names of its
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
DAMAGE.


## SymPy Development Team¶

SymPy is a team project and it was developed by a lot of people. Please refer to the AUTHORS file in the SymPy repository for up-to-date list of contributors.

Please note that that list is incomplete intentionally, because some former SymPy developers don’t want to be mentioned in the context of the SymPy or derived projects.

## Brief History¶

SymPy was started by Ondřej Čertík in 2005, he wrote some code during the summer, then he wrote some more code during the summer 2006. In February 2007, Fabian Pedregosa joined the project and helped fixed many things, contributed documentation and made it alive again. 5 students (Mateusz Paprocki, Brian Jorgensen, Jason Gedge, Robert Schwarz and Chris Wu) improved SymPy incredibly during the summer 2007 as part of the Google Summer of Code (GSoC). Pearu Peterson joined the development during the summer 2007 and he has made SymPy much more competitive and fast (from 10x to 100x) by rewriting the core from scratch. Jurjen N.E. Bos has contributed pretty printing and other patches. Fredrik Johansson has wrote mpmath and contributed a lot of patches.

SymPy has participated in every GSoC since 2007. Moderate amount of SymPy’s development has come from GSoC students.

In 2011, Ondřej Čertík stepped down as lead developer, with Aaron Meurer, who also started as a GSoC student, taking his place.

Ondřej Čertík is still active in the community, but is too busy with work and family to play a lead development role. Unfortunately, his remaining activity neither constructive nor productive anymore and SymPy just slowly dies now: most former contributors are inactive now or explicitly leaving this “friendly and welcoming” project.

This unfortunate situation was major reason to fork the SymPy as the Diofant project. Development in the new project will be open and public, without hidden double standards, centered about good, proved code and not project popularity counters. Here we believe that mathematical correctness is more important than political one.