Varnish

Varnish Cache is a web accelerator also called as a caching HTTP reverse proxy. You can install it in front of any server that speaks the HTTP protocol and configure it to cache the contents. Varnish Cache is really, really fast and will improve your web site's loading speed. One of the chief merits of Varnish Cache is the flexibility of its domain-specific language, VCL, which enables you to define how incoming requests should be tackled.

Memcached

Memcached is a generic memory object caching system for increasing the load speed of dynamic database-driven websites. It is used to lower 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 two-tier architecture. The Memcached distributed memory object caching system is used by some of the most traffic-heavy websites on the Internet and is supported by popular CMSs like Joomla and WordPress.

Node.js

Node.js is a software system for building scalable Internet apps. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, asynchronous input/output model that makes it lightweight and efficient, ideal for high-performance data-rich network 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 underlying software component that a DBMS uses to create, retrieve, update and delete data from a database. The latest version of InnoDB offers serious improvements in efficacy, reliability and usability. InnoDB provides the standard ACID-compliant transaction features, as well as foreign key support. InnoDB is included as standard in most binaries distributed by MySQL AB.