Varnish

Varnish Cache is a web accelerator also popular as an HTTP accelerator. You can install it in front of any server that speaks HTTP and configure it to cache the content. Varnish Cache is very, very fast and will boost your website's speed. One of the key merits of Varnish Cache is the flexibility of its configuration language, VCL, which allows you to define how incoming requests should be handled.

Memcached

Memcached is a general-purpose memory caching system for boosting the load speed of dynamic database-driven websites. It is used to reduce 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 object caching system uses a client/server architecture. The Memcached memory object caching system is employed by some of the most frequently visited sites on the World Wide Web and is supported by famous web applications like Joomla and WordPress.

Node.js

Node.js is a platform for writing highly scalable Internet apps. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, asynchronous input/output model that makes it lightweight and effective, great for high-performance data-heavy Internet applications. 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 relational database management system. A database engine is the underlying software component that a DBMS uses to create, read, modify and delete data from a database. The latest version of InnoDB offers significant improvements in performance, stability and functionality. InnoDB offers the standard ACID-compliant transaction properties, as well as foreign key support. It is included as standard in most binary distributions from MySQL AB.