What is WSO2 API Manager?

It is an API Management Product which has a gateway and other set of tools to tools to manage api life cycle.

There are a lot of tools like this as below:

  1. WSO2
  2. Tibco APIX
  3. CA Layer 7
  4. Apigee
  5. Axway
  6. Mashery

These tools gives you a better platform to build and manage your web services and also provides security and other throttling features to restrict the calls.