keyxpat is the first software that solves in a new way this famous problem under Windows:
keyxpat is really simple, but it had to be invented. This utility associates a key with a series of characters. To get a particular one in the series, you just have to keep the key pressed and to release it after a certain (short) time. Let's take an example:
If you hit the E key and release it right away, as usual you get an "e". Keep it pressed a bit more and you get an "é". A bit more again and this is a "è" you get this time. This ends with an "ê".
The waiting time between each character depends on your typing speed. It is configurable and is measured in milliseconds. Personnally I use 350ms. It's up to you which speed you need.
Since you don't have a timer in your head, keyxpat helps you determine when to release a key thanks to a subtle metronome that chimes out small ticks. Release the key as soon as you hear the requested number of ticks.