Eigen
Eigen is a high-level C++ template library for linear algebra, providing matrices, vectors, numerical solvers, and related algorithms. It is designed for performance, ease of use, and reliability, with a focus on expression templates to optimize compile-time operations. It is widely used in scientific computing, computer graphics, robotics, and machine learning applications.
Developers should learn Eigen when working on projects requiring efficient linear algebra operations in C++, such as 3D graphics, physics simulations, or numerical analysis. It is particularly valuable for its speed, due to compile-time optimizations, and its clean API that avoids manual memory management, making it a preferred choice over raw BLAS/LAPACK implementations for many use cases.