Varnish

Varnish Cache is a web accelerator also known as an HTTP accelerator. You can install it in front of any server that speaks the HTTP protocol and configure it to cache the content. Varnish Cache is really, really fast and will make your site load much faster. One of the important pluses of Varnish Cache is the flexibility of its domain-specific language, VCL, which permits you to determine how incoming requests should be tackled.

Memcached

Memcached is a general-purpose distributed memory caching system for speeding up dynamic database-powered sites. It is used to reduce 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 distributed memory caching system uses a client/server architecture. The Memcached memory object caching system is employed by some of the most popular sites on the Internet and is supported by famous CMSs like Joomla and WordPress.

Node.js

Node.js is a platform for writing scalable network apps. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, non-blocking input/output model that makes it lightweight and effective, ideal for high-performance data-rich applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of built-in libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source database management system. A storage engine is the primary software component that a database management system uses to create, retrieve, modify and delete data from a database. Its latest release features substantial improvements in efficiency, reliability and functionality. InnoDB offers the standard ACID transaction attributes, as well as referential integrity support. InnoDB is included as standard in most binary distributions from MySQL AB.