This book was written using Elasticsearch server 2.2 and all the examples and functions should work with this. In addition to this, you'll need a command that allows you to send HTTP request such as curl, which is available for most operating systems. Please note that all the examples in this book use the previously mentioned curl tool. If you want to use another tool, please remember to format the request in an appropriate way that is understood by the tool of your choice.
In addition to this, some chapters may require additional software, such as Elasticsearch plugins, but when needed it has been explicitly mentioned.