Dough is a personal budgeting application. It's designed to be both simple and attractive whilst being very effective at helping you keep in control of your spending. It features an attractive, to the point user interface with plenty of visual elements. It has many options for filtering and searching transactions, can import your bank statements, and you can make graphs of pretty much anything.
bgt is a program for creating and maintaining a budget from the UNIX/Linux command line. It is written in ANSI C. For number processing, it uses the Binary Coded Decimal number engine from bc. For data storage, it uses SQLite. All functionality for the program is available from the command line and does not require a GUI. It should be portable to other environments, including Windows, but it uses Unix-only directory names, so it would need some tweaking.