Varnish

Varnish Cache is a web application accelerator also called 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 improve your website's loading speed. One of the chief features of Varnish Cache is the flexibility of its configuration language, VCL, which allows you to determine how incoming requests should be dealt with.

Memcached

Memcached is a generic memory caching system for increasing the speed of dynamic database-driven sites. It is used to reduce 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 distributed memory object caching system uses a two-tier architecture. The Memcached distributed memory caching system is used by some of the most traffic-intensive websites on the Internet and is supported by famous Content Management Systems like Joomla and WordPress.

Node.js

Node.js is a software system for building highly scalable network applications. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, non-blocking input/output model that makes it lightweight and efficient, great for real-time content-intensive Internet applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built 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 database management system uses to create, retrieve, update and delete data from a database. The latest edition of InnoDB offers substantial improvements in efficacy, stability and functionality. InnoDB provides the standard ACID-compliant transaction properties, as well as declarative referential integrity support. It is included by default in most binaries distributed by MySQL AB.