An API is a programmable interface to allow two different systems to interact with each other in a controlled, authorised way. In this case the two systems being RentPro and your website. The RentPro API enables authorised users to extract property information from your RentPro account to be used for any purpose.
There are many many different types of CMS systems all written in various different computer languages. API's are designed to be language agnostic, therefore it doesn't matter what system or language the two communicating systems are written in they know how to talk to each other via a common format. With so many different languages and CMS systems it's impossible for us to supply plugins for them all. Therefore we just provide developers with the building blocks i.e. the API. If your website is built on the Joomla CMS then your web developer can write their own plugin for this using our API. Any competent web developer should be able to do this for you. You don't need to rebuild the entire website. The RentPro API is built using common formats/standards used right across the internet.
If you require a copy of our API for your website developer then please get in touch and we will forward it to you.