Xero!

GnuCash is personal and small-business financial-accounting software, freely licensed under the GNU GPL and available for GNU/Linux, BSD, Solaris, Mac OS X and Microsoft Windows.

Dolibarr ERP & CRM is a modern and easy to use open-source web software package to manage your business (customers, invoices, orders, products, stocks, agenda, e-mailings, shipments...).

Send, track and collect payments quickly. Great for teams, freelancers and service providers. FreshBooks is an easy cloud accounting app for small businesses and freelancers, specifically designed to save you time billing clients. Create professional invoices, capture expenses with ease and effortlessly track time on projects; it’s all here, plus you’ll be ready for tax time.

ZipBooks allows contractors and small businesses to send quotes and invoices to potential customers or paying clients. Create a project with ZipBooks and track the time, products, and expenses of your work. Once you are ready to send an invoice to a client, ZipBooks automatically detects unbilled activity and allows you to include any or all of the billing details. You can customize the rate of each of your team members, whether to include an attached PDF, and even add your own logo to invoices. Because we make money if you use our credit card payment partners, ZipBooks is 100% free, forever. We will never spam you, show you ads, sell your information, or watermark your invoices. »

The suite of applications Stoq is an innovative set of business management applications available as free and open source software.

FrontAccounting is a simple, but powerful, system for the entire ERP chain and covers:

The most popular version of Americas #1 small business financial software helps make your business more profitable.

Skrooge allows you to manage your personal finances, powered by KDE 4.x. Thanks to its many features, it is one of the most powerful way to enter, follow, and analyze your expenses.

New Zealand's Smart Accounting Software. With desktop and online options available, CashManager makes accounting easy!

The easiest way to track and forecast your wealth - using a calendar. Put all of your income and expenses on a calendar so its easy to see your daily balances, when bills are coming out, get reminders and see where your money is going.

Invoice Ninja is a free, open-source solution for invoicing and billing customers. With Invoice Ninja, you can easily build and send beautiful invoices from any device that has access to the web. Your clients can print your invoices, download them as pdf files, and even pay you online from within the system.

inoERP is an open source php based enterprise management system. The ERP systems contain all the required modules for running any small to mid-size businesses.The features are very similar to Oracle R12/ Fusion Application and SAP. It also contains a light weight CMS which seamlessly integrates with the ERP