Varnish

Varnish Cache is a web accelerator also popular 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 content. Varnish Cache is very, very fast and will improve your web site's speed. One of the main merits of Varnish Cache is the flexibility of its domain-specific language, VCL, which permits you to determine how incoming requests should be handled.

Memcached

Memcached is a generic distributed memory object caching system for increasing the speed of dynamic database-powered web 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 system is employed by some of the most regularly visited sites on the web and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a software platform for building highly scalable Internet 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 content-rich Internet applications. Node.js uses Google's V8 JavaScript engine, libUV, and several built-in libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source RDBMS. A database engine is the underlying software component that a DBMS uses to create, read, update and delete data from a database. The latest edition of InnoDB offers serious improvements in efficacy, dependability and usability. InnoDB provides the standard ACID-compliant database transaction properties, as well as referential integrity support. InnoDB is included as standard in most binary distributions from MySQL AB.