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 very, very fast and will increase your web site's speed. One of the key pluses of Varnish Cache is the flexibility of its domain-specific language, VCL, which enables you to choose how incoming requests should be handled.

Memcached

Memcached is a generic distributed memory object caching system for speeding up dynamic database-powered websites. It is used to decrease 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 system is used by some of the most regularly visited web sites on the web and is supported by popular web applications like Joomla and WordPress.

Node.js

Node.js is a software system for building scalable network applications. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, asynchronous input/output model that makes it lightweight and effective, perfect for high-performance content-rich network apps. Node.js uses Google's V8 JavaScript engine, libUV, and a number of built-in libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source database management system. A storage engine is the underlying software component that a database management system uses to create, retrieve, update and delete data from a database. Its latest release offers considerable improvements in efficiency, dependability and usability. InnoDB provides the standard ACID database transaction properties, as well as foreign key support. It is included as standard in most binary distributions from MySQL AB.