Varnish

Varnish Cache is a web accelerator also popular 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 boost your site's speed. One of the essential strengths of Varnish Cache is the flexibility of its configuration language, VCL, which permits you to specify how incoming requests should be tackled.

Memcached

Memcached is a generic distributed memory caching system for increasing the loading speed of dynamic database-driven 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 memory caching system uses a client'server architecture. The Memcached memory caching system is used by some of the most frequently visited websites on the web and is supported by popular CMSs like Joomla and WordPress.

Node.js

Node.js is a platform for building highly scalable network applications. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, asynchronous input/output model that makes it lightweight and efficient, great for real-time data-intensive Internet apps. Node.js uses Google's V8 JavaScript engine, libUV, and a number of built-in libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source RDBMS. A storage engine is the underlying software component that a database management system uses to create, read, modify and delete data from a database. Its latest edition offers significant improvements in efficacy, reliability and usability. InnoDB provides the standard ACID-compliant transaction attributes, along with declarative referential integrity support. InnoDB is included by default in most binary distributions from MySQL AB.