Which mailchimp plugin is this?

Hello!

Does anybodey can tell me what Mailchimp plugin this pop-up subscription is: http://www.anna-nina.nl/

I see this, but I don;t know which plugin this should be:
href=’http://www.anna-nina.nl/wp-content/plugins/mailchimp/css/ie.css?ver=3.9.2

I would like to use the same plugin and change the design.

Thanks!