anchor.diff:  
   [caption=""]
   //.Kill Bill: Physical View Of The Deployment
  -image::../assets/what_is_killbill/KillBill_Mid_level.svg[align=center]
  +image::../assets/what_is_killbill/KillBill_Mid_level.svg[width=1000,align=center]
   
   * There are two sets of _servers_, one for Kill Bill, one for Kaui. Each _server_ can either be a physical server, a VM, or a container. Either way, it will run a Tomcat Java process where Kill Bill or Kaui are deployed. Typically, two instances of Kaui and three of Kill Bill should be plenty.
   * Two (physical or virtual) load-balancers route traffic to the servers (in a _least number of connections_ or _round robin_ configuration). Assuming the network can be trusted, these load-balancers terminate SSL traffic.
  
positive.code: We refer to Kill Bill as a *platform* because of its extensibility: You can write plugins to **modify the behavior of the system** or to **integrate with third-party vendors**, such as fraud detection solutions (Accertify, Feedzai, etc.) or tax providers (Avalara AvaTax, Vertex, etc.). We offer some open-source plugins on our http://github.com/killbill/killbill[GitHub organization], but in order to match your exact business requirements, you may need to write your own.
  
  As an example, let's imagine a Kill Bill deployment with two plugins, the first one a tax plugin that will interact with a 3rd party tax provider, and the second one, a payment plugin, that will interact with a payment gateway.
  
  {empty} +
  
  [caption=""]
  //.Kill Bill: Deployment With Two Plugins
  
negative.code: 
  [caption=""]
  //.Kill Bill: Big Picture
  image::../assets/what_is_killbill/KillBill_High_level.svg[width=1000,align=center]
  
  So, in the diagram above, we can see that:
  
  