The Diofant project is a fork of the SymPy, started by Sergey B Kirpichev, last regular SymPy's commit is :commit:`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:
.. literalinclude:: ../LICENSE :language: none
SymPy Development Team
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.
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.