Decimal alternatives and similar packages
Based on the "Math" category.
Alternatively, view Decimal alternatives based on common mentions on social networks and blogs.

vector
An efficient implementation of Intindexed arrays (both mutable and immutable), with a powerful loop optimisation framework . 
statistics
A fast, high quality library for computing with statistics in Haskell. 
HerbiePlugin
GHC plugin that improves Haskell code's numerical stability 
hgeometry
HGeometry is a library for computing with geometric objects in Haskell. It defines basic geometric types and primitives, and it implements some geometric data structures and algorithms. The main two focusses are: (1) Strong type safety, and (2) implementations of geometric algorithms and data structures that have good asymptotic running time guarantees. 
computationalalgebra
GeneralPurpose Computer Algebra System as an EDSL in Haskell 
dimensional
Dimensional library variant built on Data Kinds, Closed Type Families, TypeNats (GHC 7.8+). 
mwcrandom
A very fast Haskell library for generating high quality pseudorandom numbers. 
numhask
A haskell numeric prelude, providing a clean structure for numbers and operations that combine them. 
cf
"Exact" real arithmetic for Haskell using continued fractions (Not formally proven correct) 
optimization
Some numerical optimization methods implemented in Haskell 
poly
Fast polynomial arithmetic in Haskell (dense and sparse, univariate and multivariate, usual and Laurent) 
safedecimal
Safe and very efficient arithmetic operations on fixed decimal point numbers 
equationalreasoning
Agdastyle equational reasoning in Haskell 
polynomial
Haskell library for manipulating and evaluating polynomials 
eigen
Haskel binding for Eigen library. Eigen is a C++ template library for linear algebra: matrices, vectors, numerical solvers, and related algorithms. 
vectorthunbox
Deriver for unboxed vectors using Template Haskell 
monoidsubclasses
Subclasses of Monoid with a solid theoretical foundation and practical purposes 
diagramssolve
Miscellaneous solver code for diagrams (lowdegree polynomials, tridiagonal matrices)
Less time debugging, more time building
* Code Quality Rankings and insights are calculated and provided by Lumnify.
They vary from L1 to L5 with "L5" being the highest.
Do you think we are missing an alternative of Decimal or a related project?
README
HaskellDecimal
Fixedprecision decimal numbers, where the precision is carried with the numbers at runtime.
The Decimal
type is mainly intended for doing financial arithmetic
where the number of decimal places may not be known at compile time
(e.g. for a program that handles both Yen and Dollars) and the
application must not drop pennies on the floor. For instance if you
have to divide $10 between three people then one of them has to get
$3.34.
The number of decimal places in a value is represented as a Word8, allowing for up to 255 decimal places. Functions preserve precision. Addition and subtraction operators return a result with the precision of the most precise argument, so 2.3 + 5.678 = 7.978. Multiplication and division use whatever precision is necessary up to 255 decimal places.
QuickCheck Specification
Data.Decimal includes a set of QuickCheck properties which act as both tests and a formal specification. To run the tests do:
cabal configure enabletests cabal build cabal test
or
stack test