GnuCash is a personal finance and small-business accounting software. It provides a check-book like register GUI to enter and track bank accounts, stocks, income and expenses, for double-entry accounting. It also allows to manage stock/bond/mutual fund accounts, generate graphs and reports, supports QIF/OFX/HBCI import, and transaction matching, common calculations and scheduling. It's still simple to use.
LilyPonds slogan is "Music notation for everyone". A music engraving program, devoted to producing the highest-quality sheet music possible. It brings the aesthetics of traditionally engraved music to computer printouts.
GNU Guix is a transactional package manager for the GNU system. In addition to standard package management features, Guix supports transactional upgrades and roll-backs, unprivileged package management, per-user profiles, and garbage collection. Guix uses low-level mechanisms from the Nix package manager, except that packages are defined as native Guile modules, using extensions to the Scheme language. It is possible to use Guix on top of an already installed GNU/Linux system.
A pure C library for asymmetric cryptography algorithm.Include Modified-Rabin signature scheme,Rabin encryption scheme,H. C. Williams encryption scheme.