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 contents. Varnish Cache is really, really fast and will increase your web site's speed. One of the chief attributes of Varnish Cache is the flexibility of its configuration language, VCL, which enables you to specify how incoming requests should be dealt with.

Memcached

Memcached is a general-purpose memory caching system for increasing the loading speed of dynamic database-driven 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 memory caching system uses a client/server architecture. The Memcached system is employed by some of the most traffic-heavy websites on the web and is supported by famous CMSs like Joomla and WordPress.

Node.js

Node.js is a platform for building scalable Internet applications. Written in JavaScript, Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, suitable for real-time content-intensive apps. 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 DBMS. A database engine is the main software component that a DBMS uses to create, read, update and delete data from a database. The latest release of InnoDB features substantial improvements in efficiency, reliability and functionality. InnoDB offers the standard ACID-compliant transaction features, along with declarative referential integrity support. InnoDB is included as standard in most binary distributions from MySQL AB.