GnuCash is a personal and small-business finance manager with a check-book like register GUI to enter and track bank accounts, stocks, income and expenses. GnuCash is designed to be simple and easy to use but still based on formal accounting principles.
Scwm is the Scheme Configurable/Constraints Window Manager, a window manager with a powerful dynamic configuration language based on Guile Scheme. Scwm has many, many advanced features, often implemented in the configuration language itself.
track time spent, keep a diary, to-do list, generate reports, bills
GnoTime (formerly GTT, the Gnome Time Tracker) is a desktop utility for tracking the amount of time spent on projects, keeping a to-do list, maintaining a diary, and generating reports and invoices based on that time.