Finely dice the jalapeno pepper. Remove the ribs and seeds for a mild heat or keep them in for more of a kick.
Add all of the ingredients to a small bowl and mix. Season to taste as needed. Refrigerate until chilled, approximately 30 minutes. This salsa is best the same day as the corn tends to dry out if made too far in advance. You can correct this by adding more lime or a little water to freshen it up again.