Varnish

Varnish Cache is a web application accelerator also known as a caching HTTP reverse proxy. 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 site's speed. One of the essential strengths 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 general-purpose memory object caching system for boosting the loading speed of dynamic database-powered sites. 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 object caching system uses a client/server architecture. The Memcached distributed memory object caching system is used by some of the most regularly visited websites on the World Wide Web and is supported by popular CMSs like Joomla and WordPress.

Node.js

Node.js is a software platform for building scalable Internet apps. Written in JavaScript, Node.js uses an event-based, asynchronous input/output model that makes it lightweight and effective, great for real-time content-rich Internet apps. 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 database management system. A storage engine is the principal software component that a DBMS uses to create, read, update and delete data from a database. Its latest release features serious improvements in efficiency, stability and functionality. InnoDB offers the standard ACID transaction features, as well as referential integrity support. InnoDB is included as standard in most binaries distributed by MySQL AB.