Varnish

Varnish Cache is a web application accelerator also known 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 improve the speed of your website. One of the major merits of Varnish Cache is the flexibility of its domain-specific language, VCL, which permits you to specify how incoming requests should be handled.

Memcached

Memcached is a general-purpose memory caching system for boosting the speed of dynamic database-driven websites. It is used to decrease the number of times an external data source (such as a DB or API) is read by caching data and objects in RAM. The Memcached memory object caching system uses a client/server architecture. The Memcached memory caching system is employed by some of the most regularly visited websites on the Internet and is supported by popular CMSs like Joomla and WordPress.

Node.js

Node.js is a software system for writing scalable network apps. Written in JavaScript, Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, great for high-performance data-heavy network apps. 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 relational database management system. A database engine is the main software component that a database management system uses to create, retrieve, update and delete data from a database. The latest release of InnoDB offers serious improvements in efficiency, security and usability. InnoDB provides the standard ACID-compliant transaction features, as well as foreign key support. InnoDB is included by default in most binary distributions from MySQL AB.