The About dialog is a special dialog window which shows the copyright information, current version of your Actual Window Manager copy and its registration status.
Also, there is a button to open the Check for Updates window and two special hyperlinks. The first one leads to the Actual Tools main website where you can read the news about updates, download them, contact the other users at the forum etc. The second one creates an empty e-mail message addressed to Actual Tools Support Service, it is useful in the case you want to ask some questions or make a suggestion about Actual Window Manager.
You can close this dialog by clicking either the standard Close title button or the Close button at bottom of the window.