Asterisk + firefox + click2dial plugin

You can install asterisk click2dial and Status-4-Evar (needed to enable the statusbar in firefox, removed since Firefox 50 pr so) extensions on firefox to

• dial a number writing it in the text area in the statusbar
• right-click on a phone number in a web page to dial it
• get notifications on incoming callings
• automatically open a web page (CRM, ERP, ....) with information about the caller