Varnish

Varnish Cache is a web accelerator also referred to as a caching HTTP reverse proxy. You can install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast and will boost the speed of your website. One of the main merits of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which allows you to determine how incoming requests should be tackled.

Memcached

Memcached is a generic distributed memory caching system for increasing the speed of dynamic database-powered websites. It is used to decrease 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 object caching system uses a client'server architecture. The Memcached system is employed by some of the most regularly visited web sites on the Internet and is supported by famous CMSs like Joomla and WordPress.

Node.js

Node.js is a software platform for building highly scalable network apps. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, asynchronous I/O model that makes it lightweight and efficient, excellent for high-performance content-heavy Internet applications. Node.js uses Google's V8 JavaScript engine, libUV, and several in-built libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source DBMS. A storage engine is the primary software component that a database management system uses to create, retrieve, modify and delete data from a database. The latest version of InnoDB offers serious improvements in performance, security and functionality. InnoDB provides the standard ACID database transaction features, along with declarative referential integrity support. InnoDB is included as standard in most binary distributions from MySQL AB.