Within a matter of minutes you will be able to enter your personal
      finance information and generate color graphs that represent your
      financial status. If you can use the register in the back of your
      checkbook - you can use GnuCash! Type directly into the register, tab
      between fields, and use quick-fill to automatically complete
      transactions. The interface is customizable from within the application
      itself.
Easy to Use Menus: GnuCash menus conform
          to the GNOME Human Interface Guidelines. This means that they are
          simple and similar in appearance to many other GNOME
          applications.
Documentation: GnuCash has built-in Help
          and extensive User’s Guide documentation.
Import Methods: GnuCash supports many
          ways to input transactions besides manual entry. If you can access
          your bank accounts on-line, this is especially useful, as most banks
          and credit card companies support one of the following import
          methods. You will spend less time entering data and more time
          analyzing results.
Quicken Import File (QIF): Import Quicken QIF style files, a popular file format with many commercial personal finance software packages.
Open Financial Exchange (OFX):
              GnuCash has been the first free software application to support the
              Open Financial Exchange protocol. Many financial institutions
              are moving towards this format.
Home Banking Computer Interface
              (HBCI): GnuCash has been the first free software
              application to support the German Home Banking Computer
              Interface protocol. This protocol includes statement download,
              initiates bank transfers, and makes direct debits
              possible.
Reports: GnuCash comes with over 30
          prebuilt reports, including Account Summary, Income, Expenses,
          Transaction Report, Balance Sheet, Profit&Loss, Portfolio
          Valuation, and many others. Reports support graphical views of the
          data, including pie charts, bar charts, and scatter plots. The
          reports can be exported to HTML files, and are easily
          customized.
Scheduled Transactions: GnuCash now has
          the ability to automatically create and enter transactions, or
          remind you when these transactions are due, giving you the choice of
          entering, postponing or removing the automated transaction.
Mortgage and Loan Repayment Assistant: Used to set up a variable payment loan scheduled transaction.
Easy Account Reconciliation: Integrated
          reconciliation makes reconciling your GnuCash accounts with
          statements simple and effective.
Multi-platform Compatibility:
          GnuCash is supported on a variety
          of platforms and operating systems. The list of fully
          supported operating systems (and platforms) is for
          
GnuCash 3.10GNU/Linux (x86, x86_64), FreeBSD (x86, x86_64), OpenBSD (x86, x86_64), Apple MacOS (64-bit Intel), and Microsoft Windows (Windows 7 and later).
GnuCash ≤ 2.6.21Apple MacOS (32-bit Intel, PPC) and Microsoft Windows (XP and Vista).
GnuCash ≤ 2.2.9Microsoft Windows (2000).
GnuCashhave been known to work with SGI IRIX (MIPS), IBM AIX 4.1.5 (RS/6000), Unixware 7 (Intel), SCO OpenServer 5.0.4 (Intel), and Solaris (Sparc) but their current status is unknown.
GnuCash includes a number of investment features that allow you to track all your investments. With GnuCash you can track stocks individually (one per account) or in a portfolio of accounts (a group of accounts that can be displayed together).
GnuCash supports online stock and mutual fund quotes. This means you no longer need to look up stock prices one at a
          time. The process can be automated, and you can see the latest value of your stocks.
GnuCash is truly an application that works with and understands
      users from all around the world. There are many built-in features to
      facilitate interaction with the international world we live in
      today.
Native Languages: GnuCash has been
          translated into 56 languages. The best ones, with over 90%
          translated, are Croatian, German, Hebrew, Portuguese,
          Spanish, and Ukrainian. Almost as good, with over 80%
          translated, are Catalan, Dutch, Japanese, Latvian, Russian,
          Serbian, and Turkish.
          [1]
International Format Handling: GnuCash
          understands that different countries display the date and numbers differently.
          You are able to work with the date and number formats you are accustomed
          to.
Multiple Currencies and Currency Trading: Multiple currencies are supported and can be bought and sold (traded). Currency movements between accounts remain fully balanced if "Trading Accounts" is enabled.
On-line exchange rates:
          With GnuCash, you no longer need look up your exchange rates one at a
          time. The process can be automated, to always present you with the
          account values converted to your preferred currency using the latest
          exchange rates.
GnuCash has many features to support the needs of the business
      accounting community.
Accounts Receivable/Payable: GnuCash has
          an integrated Accounts Receivable and Accounts Payable system. You
          can track Customers, Vendors, Invoicing and Bill Payment, and use
          different Tax and Billing Terms in a small business.
Depreciation: GnuCash can track
          depreciation of capital assets.
Reports: GnuCash offers a wide variety of
          ready-to-use business reports.
For those knowledgeable in accounting, here is a list of GnuCash’s
      accounting features.
Double Entry: Every transaction must debit one account and credit others by an equal amount. This ensures the “books balance” - that the difference between income and expense exactly equals the sum of all bank, cash, stock and other assets.
Split Transactions: A single transaction can be split into several pieces to record taxes, fees, and other compound entries.
Chart of Accounts: A master account can have a hierarchy of detail accounts underneath it. This allows similar account types such as Cash, Bank, or Stock to be grouped into a master account such as “Assets”.
General Journal: One register window can display multiple accounts at the same time. This eases the trouble of tracking down typing/entry errors. It also provides a convenient way of viewing a portfolio of many stocks, by showing all transactions in that portfolio.
Income/Expense Account Types (Categories): These categorize your cash flow and, when used properly with the double-entry feature, will provide an accurate Profit&Loss statement.
[1] If you want to create or improve the translation of your language see https://wiki.gnucash.org/wiki/Translation.