Moneychanger is a GUI built on top of Open Transactions, a financial crypto library. Moneychanger can be used to create pseudonyms, issue currencies, open accounts, withdraw and deposit cash (untraceable digital cash), write and deposit cheques, trade on markets, and much, much more.
Bitcoin is a peer-to-peer electronic cash system that is completely decentralized, without the need for a central server or trusted parties. Users hold the crypto keys to their own money and transact directly with each other, with the help of a P2P network to check for double-spending.
Skrooge is a personal finances manager powered by KDE. It allows you to keep track of your expenses and income, categorize them, and build reports. You can also manage your investments and see how they perform over time. Multiple accounts are supported. Some of the features included are advanced graphical reports, tabs that help you to organize your work, infinite undo/redo (even after the file was closed), instant filtering on operations and reports, infinite category levels, mass update operations, scheduled operations, tracking of refunds, automatic processing based on search conditions, and support for multiple currencies.