Probo is built by Zivtech. We are mainly a Drupal shop, but Probo is not a Drupal-specific tool. We use it with any web technology, including WordPress.
One of our clients using WordPress is All Ages Productions, a video production company here in Philadelphia. All Ages created the Probo explainer video for us, and in return we help them support their WordPress site, so they got to experience the product they were helping us market as end-users.