Mix your own colours. A web-builder's tool, a learning experience, or just fun. Shows colours and the geek numbers (hexadecimal codes) that are used to make different shades. Make any colour you like; view against complementary colour.

How long since your wedding, since Elvis died, Pearl Harbour? How long until end of term, till your silver wedding? Enter any date and find out exactly how long since or until then.

If you have fixed-rate investments or some other reason to calculate compound interest, this could be for you. Beats working it out by hand or consulting tables.

Think of fuel consumption in Miles per Gallon? But buy your petrol in litres (a mainly British problem) or distances are in kms, or the gallons are American? Find working out fuel consumption a pain? Say goodbye to metric misery and computational confusion, wherever you live, with a script that does it for you. Just enter miles or km, and litres or gallons (Imperial or US), and bingo!

If you need to work out percentages but are innumerate, subnormal, or lack a calculator or pen and paper, look no further than this. It is really here because it is the first Javascript that this web-meister ever got to work. A milestone in the history of computing.