Varnish

Varnish Cache is a web application accelerator also popular as a caching HTTP reverse proxy. You can install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast and will improve the loading speed of your web site. One of the major virtues of Varnish Cache is the flexibility of its configuration language, VCL, which permits you to specify how incoming requests should be tackled.

Memcached

Memcached is a generic distributed memory object caching system for increasing the load speed of dynamic database-driven web sites. It is used to lower 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 object caching system uses a client/server architecture. The Memcached memory object caching system is employed by some of the most regularly visited sites on the World Wide Web and is supported by famous web applications 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, non-blocking input/output model that makes it lightweight and effective, perfect for real-time data-heavy Internet 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 RDBMS. A storage engine is the main software component that a database management system uses to create, retrieve, modify and delete data from a database. Its latest version features significant 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 as standard in most binaries distributed by MySQL AB.