Gnumeric is a lightweight spreadsheet program that is fast and feature complete.
Much like its chief open source competitors OpenOffice and LibreOffice, its graphical user interface is nothing fancy. What it lacks in colorful design or exciting visual menu displays, however, it surpasses with its format flexibility and easy operation.
It might seem counterproductive to use a spreadsheet application outside a business suite, but no real reason justifies not doing so.
rest here