Varnish

Varnish Cache is a web accelerator also known as an HTTP accelerator. You can install it in front of any web server that speaks HTTP and configure it to cache the contents. Varnish Cache is very, very fast and will increase the speed of your web site. One of the chief advantages of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which permits you to determine how incoming requests should be dealt with.

Memcached

Memcached is a general-purpose distributed memory caching system for boosting the loading speed of dynamic database-driven websites. It is used to lower the number of times an external data source (such as a database or API) is read by caching data and objects in RAM. The Memcached distributed memory caching system uses a two-tier architecture. The Memcached distributed memory caching system is used by some of the most frequently visited websites on the World Wide Web and is supported by popular Content Management Systems like Joomla and WordPress.

Node.js

Node.js is a software system for building highly scalable network apps. Written in JavaScript, Node.js uses an event-based, asynchronous input/output model that makes it lightweight and effective, great for high-performance content-heavy Internet apps. Node.js uses Google's V8 JavaScript engine, libUV, and a number of built-in libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source RDBMS. A database engine is the primary software component that a DBMS uses to create, retrieve, modify and delete data from a database. The latest version of InnoDB offers considerable improvements in performance, security and usability. InnoDB provides the standard ACID-compliant database transaction properties, as well as declarative referential integrity support. InnoDB is included by default in most binary distributions from MySQL AB.