You need to install first a Java machine, like Oracle Java SE, or Open JDK if you are on Linux
Just download the version for your OS, and install. You should be able to start the Studio.
Bonita BPM Studio comes with a H2 database for development purpose.
Bonita BPM Studio is intended for development only. When your processes are ready, you must deploy them on the Platform.
Bonita BPM Platform (Portal + Engine)
You will need first to install a Java machine, like for the Studio. However, if your hardware is a headless server, you can install a headless version of Java, it is lighter.
Bonita Platform is not a standalone application, you need to run it in a Java application server, for example, Tomcat or Jboss. Of course, feel free to use the one you want.
You can download the Deploy Bundle if you want to install the Platform yourself in your application server.
However, to ease the installation process for production, Bonitasoft provide ready to use multi OS Bundles: one with Tomcat and one with Jboss.
You can use the default H2 provided database, or set the one you want.
Bonitasoft empowers development teams with Bonita, the open-source and extensible platform to solve the most demanding process automation use cases. The Bonita platform accelerates delivery of complex applications with clear separation between capabilities for visual programming and for coding. Bonita integrates with existing solutions, orchestrates heterogeneous systems, and provides deep visibility into processes across the organization.