Varnish

Varnish Cache is a web accelerator also famous as an HTTP accelerator. You can install it in front of any web server that speaks the HTTP protocol and configure it to cache the content. Varnish Cache is very, very fast and will speed up your web site. One of the main virtues of Varnish Cache is the flexibility of its domain-specific language, VCL, which enables you to determine how incoming requests should be dealt with.

Memcached

Memcached is a generic distributed memory object caching system for boosting the loading speed of dynamic database-powered web sites. It is used to reduce 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 memory caching system is employed by some of the most traffic-heavy web sites on the World Wide Web and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a software platform for building highly scalable network applications. Written in JavaScript, Node.js uses an event-driven, non-blocking input/output model that makes it lightweight and efficient, suitable for real-time content-heavy network applications. Node.js uses Google's V8 JavaScript engine, libUV, and several in-built libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source RDBMS. A storage engine is the principal software component that a DBMS uses to create, read, modify and delete data from a database. The latest version of InnoDB features serious improvements in performance, stability and functionality. InnoDB offers the standard ACID database transaction features, as well as referential integrity support. It is included by default in most binary distributions from MySQL AB.