Yacas (Yet Another Computer Algebra System) is a small and highly flexible general-purpose Computer Algebra System (CAS). The syntax uses an infix-operator grammar parser. The distribution contains a small library of mathematical functions, but its real strength is in the language in which you can easily write your own symbolic manipulation algorithms. The core engine supports arbitrary precision arithmetic and is able to execute symbolic manipulations on various mathematical objects by following user-defined rules. For detailed information on yacas features and usage, see http://www.yacas.org.
Yacas is available for a variety of platforms. See http://www.yacas.org/getting_started/downloads/ for binary packages and installation instructions. Read https://yacas.readthedocs.io/en/latest/getting_started/index.html for instructions on how to compile yacas from sources.
Yacas is distributed under the GNU LESSER GENERAL PUBLIC LICENSE v2.1 or, at your discretion, any later version.