Varnish

Varnish Cache is a web accelerator also called 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 really, really fast and will boost your website's loading speed. One of the key pluses of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which permits you to specify how incoming requests should be tackled.

Memcached

Memcached is a generic memory caching system for increasing the load speed of dynamic database-driven websites. It is used to decrease 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 distributed memory caching system uses a client'server architecture. The Memcached memory object caching system is used by some of the most traffic-heavy websites on the web and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a software system for writing highly scalable network apps. Written in JavaScript, Node.js uses an event-based, asynchronous input/output model that makes it lightweight and efficient, ideal for real-time content-intensive 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 database engine is the principal software component that a DBMS uses to create, read, modify and delete data from a database. Its latest release features serious improvements in efficiency, reliability and functionality. InnoDB provides the standard ACID database transaction properties, as well as foreign key support. InnoDB is included as standard in most binary distributions from MySQL AB.