GnuCash is one I really like.
Good suggestions from the other posters. Take a look at GnuCash, if you want a personal accounting software that can support a single user running a business that is not incorporated.However, if you are planning to incorporate or may need more people to use this software in the future, look at TurboCash for accounting. It can be upgraded to a multi-user version suitable for up to 5 users.PostBooks and SQL-Ledger are Business Suites (also known as ERP) that have additional features to handle operations of a business, in addition to accounting. The downside is that these Business Suites are high maintenance.My recommendation would be osFinancials. This is also free and open source software:1. osFinancials has accounting, inventory control and Point of Sale (POS) integrated.2. You can start with the osFinancials single user embedded version, which is low maintenance.3. As the business grows you can upgrade to multi-user or add plug-ins for contact management (CRM) or eCommerce. So, if you are selling on the internet now, or are planning to do so in the future, this will make it easier.You can see a list of companies using osFinancials here:http://www.osfinancials.org/mediawiki/in��Installation and User Guides (in Dutch and English) are available here:http://www.osfinancials.org/mediawiki/in��The discussion forum (in Dutch and English) is here:http://www.osfinancials.org/index.php?op��
There s a few different software suites that are free that will do exactly what you want. Your best bet is probably to search for: open source alternative for quick books, in your favorite search engine. I ve tried a few of them and for a small / medium sized business they all worked just fine.My personal favorite one was http://postbooks.org/ they have a really strong community base and are still actively developing and adding to it.Others I ve used and had success with are:http://www.turbocashuk.com/index.html - turbocashhttp://www.sql-ledger.org/ - sql ledgerhttp://www.appgen.com/aptus/my_books_pro�� - my bookshttp://moneydance.com/ - money dancegood luck.