Varnish

Varnish Cache is a web application accelerator also famous 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 the speed of your web site. One of the important virtues of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which allows you to choose how incoming requests should be dealt with.

Memcached

Memcached is a general-purpose memory object caching system for speeding up dynamic database-driven web sites. It is used to lower 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 caching system uses a client'server architecture. The Memcached system is employed by some of the most traffic-hungry sites on the Internet and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a software platform for writing highly scalable network applications. Written in JavaScript, Node.js uses an event-driven, asynchronous input/output model that makes it lightweight and efficient, perfect for high-performance data-intensive network apps. 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 relational database management system. A storage engine is the main software component that a DBMS uses to create, retrieve, update and delete data from a database. Its latest version features serious improvements in efficiency, dependability and usability. InnoDB provides the standard ACID-compliant database transaction features, along with referential integrity support. InnoDB is included by default in most binaries distributed by MySQL AB.