How to debounce a switch?

Mechanical-switch keyboards use real switches, one under each key. Depending on the construction of the switch, these keyboards have varying responses and travel times. Notable keyboards utilizing this technology are the Apple Extended II, and its modern imitator, the Matias Tactile Pro. These two keyboards use ALPS switches. Cherry Corporation of Germany also makes mechanical switches used in special purpose and high end keyboards. In India, the TVS Gold mechanical keyboard is very popular in spite of the fact that it costs about five times what a membrane keyboard costs. The Matias Tactile Pro is a decent approximation of the Apple Extended II keyboard, however the grade of the plastic is noticeably cheaper. Its construction , besides having decent quality key-switches, is less than par, with flimsy keyboard risers on the bottom of the keyboard and USB ports that are too tight. Although the keyboard has these quality flaws, it's still better than most available keyboards today, except probably the IBM Model M replacements.