Varnish

Varnish Cache is a web application accelerator also referred to as a caching HTTP reverse proxy. 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 increase your website's speed. One of the chief strengths of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which enables you to define how incoming requests should be dealt with.

Memcached

Memcached is a general-purpose memory caching system for boosting the load speed of dynamic database-powered 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 two-tier architecture. The Memcached distributed memory object 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 scalable network apps. Written in JavaScript, Node.js uses an event-driven, asynchronous input/output model that makes it lightweight and efficient, excellent for high-performance content-intensive network apps. 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 principal software component that a database management system uses to create, read, update and delete data from a database. The latest release of InnoDB features serious improvements in performance, reliability and usability. InnoDB offers the standard ACID-compliant transaction features, along with referential integrity support. InnoDB is included as standard in most binaries distributed by MySQL AB.