LAPACK provides routines for solving systems of simultaneous linear equations, least-squares solutions of linear systems of equations, eigenvalue problems, and singular value problems. The associated matrix factorizations (LU, Cholesky, QR, SVD, Schur, generalized Schur) are also provided, as are
... [More] related computations such as reordering of the Schur factorizations and estimating condition numbers. Dense and banded matrices are handled, but not general sparse matrices. In all areas, similar functionality is provided for real and complex matrices, in both single and double precision.
Note: Ohloh's statistics are not accurate. LAPACK has dozens of major contributors, but most do not use any form of source control. Contributions are merged by only a few people, and then only in bursts. [Less]
This project is a joint project between Debian, Octave and Scilab in order to provide a common and maintained version of arpack.
Indeed, no single release has been published by Rice university for the last decade and since many software (Octave, Scilab, R, Matlab...) forked it and implemented
... [More] their own modifications, arpack-ng aims to tackle this by providing a common repository and maintained versions. [Less]