Open Source Credits

starring — the engines

MPFI 1.5.3 Nathalie Revol · Fabrice Rouillier · INRIA Arbitrary-precision interval arithmetic — every reading is an enclosure guaranteed to contain the true value. LGPL-2.1+

FLINT: Fast Library for Number Theory, 2026. Version 3.4.0, The FLINT team.F. Johansson. "Arb: efficient arbitrary-precision midpoint-radius interval arithmetic" Fast number theory · ball arithmetic (Arb) · exact reals (Calcium). Two of the eight engines are built on it, which is why they are never counted as independent of each other. LGPL-2.1+

LibBF Fabrice Bellard Arbitrary-precision binary floats · no dependency on any other library. Its hyperbolic functions and Gamma are composed by Ultimath over LibBF exp/log, not provided by LibBF itself. MIT

PARI/GP 2.15.4 Karim Belabas · the PARI group Arbitrary-precision reals. Ultimath builds it <em>without GMP</em>, so it runs on its own integer kernel and its own transcendental functions — the point of having it at all. GPL-2.0+

NTL 11.6.0 Victor Shoup Arbitrary-precision reals with an exact integer mantissa: a value is exact, only operations round. Its tangent, hyperbolics, inverse trigonometry and Gamma are composed by Ultimath, not provided by NTL. LGPL-2.1+

SymEngine 0.14.0 The SymEngine development team Symbolic expressions. Ultimath evaluates the tree only at the very end, so a cancellation happens before any rounding can. MIT

the layers beneath

GMP 6.3.0 Torbjörn Granlund and contributors Arbitrary-precision integers. Five of the eight engines rest on it — which is exactly why independence is read by layer here, and why two engines are built to avoid it. LGPL-3.0+ / GPL-2.0+

GNU MPFR 4.2.1 The MPFR team · INRIA Correctly-rounded arbitrary-precision floats. Underneath MPFI, and underneath what SymEngine finally evaluates. LGPL-3.0+

GNU MPC 1.3.1 Andreas Enge · Philippe Théveny · Paul Zimmermann Correctly-rounded complex arithmetic over MPFR, used by SymEngine off the real axis. LGPL-3.0+

server

Drogon An Tao C++ HTTP framework MIT

gRPC RPC framework Apache-2.0

Protocol Buffers Kenton Varda Serialization BSD-3

PostgreSQL · libpqxx Michael Stonebraker · Jeroen Vermeulen Database · C++ client PostgreSQL · BSD-3

OpenSSL Eric A. Young · Tim Hudson TLS / crypto Apache-2.0

supporting cast

Boost The Boost authors C++ libraries · memory pools · dynamic loading BSL-1.0

Flex · Bison Vern Paxson · Robert Corbett Lexer · parser generators · the expression grammar BSD-2 · GPL-3 + exception

spdlog · fmt Gabi Melman · Victor Zverovich Logging · formatting MIT

yaml-cpp · JsonCpp Jesse Beder · Baptiste Lepilleur Config · JSON MIT

xxHash Yann Collet Hashing BSD-2

ICU Unicode Unicode License

this website

Hugo Steve Francia Static site generator Apache-2.0

KaTeX Khan Academy and contributors LaTeX rendering — the closed forms shown above the digits MIT

Inter · IBM Plex Mono Rasmus Andersson · Mike Abbink Typefaces OFL-1.1

co-written with

Claude AI pair programmer — SaaS infrastructure Anthropic

Flupke68 Creator — the multi-engine architecture, the expression grammar and the product. The libraries above are their authors&rsquo; work. Human