TurboCASH - TurboCASH Accounting Free and Open Source Accounting Software for Small to Medium Business.
Grisbi - Accounting for everyone !
GnuCash - A personal and small-business financial-accounting software, licensed under GNU/GPL and available for Linux, Windows, Mac OS X, BSD, and Solaris.
Ledger-cli.org - Ledger is a powerful, double-entry accounting system that is accessed from the UNIX command-line.
Xero - Xero is online accounting for your small business.
Gnuaccounting - Gnuaccounting is a Free Java cross-platform accounting and bookkeeping application. Features