Business & Commerce
The proliferation of software to aid in the management of business projects in a variety of fields has allowed people a large degree of freedom in choosing what kind of software they would like to use. Business and commerce software and apps can provide a whole host of functionality: Managing your projects, businesses, accounting and finances; monitoring your employees; supporting your customers; and even doing your shopping through online stores, auctions or classifieds with online payment or banking.
Most popular apps

GnuCash
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.

Cashew
Track your finances with Cashew and understand your money flow. Set budgets to monitor your financial progress and foster responsible spending. Cashew is more than an app, it's your personal guide.
PayPal
A secure online payment solution offering buyer and seller protection, no fees for sending, and seamless integration with banks in 200+ countries.
Spliit
Spliit is a minimalist application to track and share expenses with your friends and family.
Amazon
Amazon is an American multinational technology company which focuses on e-commerce, cloud computing, digital streaming, and artificial intelligence.

Liberapay
Liberapay is a way to donate money recurrently to people whose work you appreciate.

Wealthfolio
Wealthfolio is a simple, desktop-based investment tracker. Your financial data is stored safely on your own computer Ditch the spreadsheets, forget about those pesky subscription fees, and no more worries about SaaS services playing around with your data.
Joomla
Joomla is an award-winning content management system (CMS), which enables you to build web sites and powerful online applications. Many aspects, including its ease-of-use and extensibility, have made Joomla the most popular web site software available.