Varnish

Varnish Cache is a web accelerator also known as a caching HTTP reverse proxy. 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 your website's speed. One of the essential virtues of Varnish Cache is the flexibility of its domain-specific language, VCL, which enables you to determine how incoming requests should be dealt with.

Memcached

Memcached is a general-purpose memory object caching system for increasing 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 memory caching system uses a two-tier architecture. The Memcached distributed memory caching system is used by some of the most popular web sites on the web and is supported by famous web applications like Joomla and WordPress.

Node.js

Node.js is a software platform for building highly scalable Internet apps. Written in JavaScript, Node.js uses an event-based, non-blocking I/O model that makes it lightweight and effective, suitable for real-time content-intensive network applications. Node.js uses Google's V8 JavaScript engine, libUV, and several in-built libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source DBMS. A database engine is the principal software component that a database management system uses to create, read, update and delete data from a database. The latest version of InnoDB offers considerable improvements in efficacy, reliability and usability. InnoDB provides the standard ACID-compliant database transaction attributes, as well as foreign key support. InnoDB is included by default in most binary distributions from MySQL AB.