Distinctive features of the library are:

• Support for several programming languages with identical APIs (as of 2023, it supports C++, C#, FreePascal/Delphi, VB.NET, Python, and Java)
• Self-contained code with no mandatory external dependencies and easy installation
• Portability (it was tested under x86/x86-64/ARM, Windows and Linux)
• Two independent backends (pure C# implementation, native C implementation) with automatically generated APIs (C++, C#, ...)
• Same functionality of commercial and GPL versions, with enhancements for speed and parallelism provided in the commercial version

The most actively developed parts of ALGLIB are:

• Linear algebra, offering a comprehensive set of both dense and sparse linear solvers and factorizations
• Interpolation, featuring standard algorithms like polynomials and 1D/2D splines, as well as several unique large-scale interpolation/fitting algorithms. These include penalized 1D/2D splines, fast thin plate splines and fast polyharmonic splines, all scalable to hundreds of thousands of points.
• Least squares solvers, including linear/nonlinear unconstrained and constrained least squares and curve fitting solvers
• Optimization, with LP, QP and NLP solvers, derivative-free global solvers and multiobjective optimization algorithms.
• Data analysis, with various algorithms being implemented

The other functions in the library include:

• Fast Fourier transforms
• Numerical integration
• Ordinary differential equations
• Special functions
• Statistics (descriptive statistics, hypothesis testing)
• Multiple precision versions of linear algebra, interpolation and optimization algorithms (using MPFR for floating point computations)

• List of numerical analysis software
• List of numerical libraries

• Official ALGLIB website