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 contents. Varnish Cache is really, really fast and will boost your web site's speed. One of the major advantages of Varnish Cache is the flexibility of its configuration language, VCL, which enables you to specify how incoming requests should be dealt with.

Memcached

Memcached is a general-purpose distributed memory object caching system for increasing the speed of dynamic database-powered 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 distributed memory object caching system uses a two-tier architecture. The Memcached distributed memory caching system is used by some of the most traffic-hungry web sites on the Internet 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 effective, excellent for high-performance data-heavy network 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 storage engine is the primary software component that a DBMS uses to create, retrieve, update and delete data from a database. Its latest release offers substantial improvements in performance, stability and usability. InnoDB offers the standard ACID-compliant transaction attributes, as well as declarative referential integrity support. InnoDB is included by default in most binary distributions from MySQL AB.