The entire Plesk Billing platform was built around making it as extensible as possible. We encourage third-party development on our product, and this page is dedicated to providing the resources to make this as easy as possible.
Third-party developers can develop additional functions within the Plesk Billing client & administrative areas, as well as interface externally with Plesk Billing using the powerful MBAPI.
If you have produced custom work and wish to share it with the Plesk Billing community, feel free to show off what you've done in our forums!