Varnish

Varnish Cache is a web accelerator also known as a caching HTTP reverse proxy. You can install it in front of any web server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast and will improve your website's speed. One of the chief virtues of Varnish Cache is the flexibility of its configuration language, VCL, which enables you to define how incoming requests should be handled.

Memcached

Memcached is a generic memory object caching system for boosting the 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 two-tier architecture. The Memcached system is used by some of the most regularly visited web sites on the web and is supported by famous web applications like Joomla and WordPress.

Node.js

Node.js is a software system for building scalable Internet applications. Written in JavaScript, Node.js uses an event-driven, non-blocking input/output model that makes it lightweight and effective, ideal for high-performance content-rich apps. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source relational database management system. A database engine is the primary software component that a database management system uses to create, read, modify and delete data from a database. The latest release of InnoDB features considerable improvements in performance, reliability and functionality. InnoDB offers the standard ACID-compliant transaction features, as well as referential integrity support. InnoDB is included as standard in most binaries distributed by MySQL AB.