WordPress.org

This plugin will allow you to have a sidebar widget that shows how many posts you published each month. Displayed like a calendar, you can navigate between years using "previous" and "next" buttons.

Some features include:

• Data is reloaded using AJAX. This means that changing the year will not reload the whole page.
• Comes with a bundled CSS file with a default style.
• The default CSS can be disabled so you can use your theme's CSS file to style it.
• It's a Widget, so you can move it around your sidebar as you wish.
• Uses jquery and jquery-ui for AJAX reloading and visual effects.