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 increase your site's loading speed. One of the main virtues of Varnish Cache is the flexibility of its configuration language, VCL, which enables you to choose how incoming requests should be handled.

Memcached

Memcached is a general-purpose distributed memory object caching system for increasing the speed of dynamic database-powered 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 memory caching system uses a client'server architecture. The Memcached memory object caching system is employed by some of the most traffic-intensive web sites on the Internet and is supported by famous Content Management Systems like Joomla and WordPress.

Node.js

Node.js is a software platform for writing highly scalable Internet apps. Written in JavaScript, Node.js uses an event-driven, asynchronous input/output model that makes it lightweight and effective, suitable for high-performance content-rich Internet applications. Node.js uses Google's V8 JavaScript engine, libUV, and several built-in libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source RDBMS. A database engine is the principal software component that a database management system uses to create, read, modify and delete data from a database. The latest version of InnoDB offers considerable improvements in performance, security and usability. InnoDB offers the standard ACID-compliant transaction properties, along with declarative referential integrity support. It is included as standard in most binaries distributed by MySQL AB.