Varnish

Varnish Cache is a web accelerator also popular as a caching HTTP reverse proxy. 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 boost your web site's speed. One of the main pluses of Varnish Cache is the flexibility of its domain-specific language, VCL, which allows you to choose how incoming requests should be tackled.

Memcached

Memcached is a general-purpose distributed memory caching system for speeding up dynamic database-driven sites. 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 object caching system uses a client/server architecture. The Memcached system is employed by some of the most frequently visited web sites on the web and is supported by popular web applications like Joomla and WordPress.

Node.js

Node.js is a software platform for writing scalable Internet apps. Written in JavaScript, Node.js uses an event-based, asynchronous input/output model that makes it lightweight and effective, ideal for real-time data-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 RDBMS. A database engine is the underlying software component that a database management system uses to create, read, update and delete data from a database. The latest version of InnoDB offers substantial improvements in efficiency, stability and functionality. InnoDB offers the standard ACID-compliant database transaction properties, as well as declarative referential integrity support. InnoDB is included by default in most binary distributions from MySQL AB.