Varnish

Varnish Cache is a web accelerator also popular as an HTTP accelerator. You can install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast and will improve your website's speed. One of the important features of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which permits you to determine how incoming requests should be tackled.

Memcached

Memcached is a generic distributed memory object caching system for increasing the load speed of dynamic database-powered 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 distributed memory object caching system uses a client/server architecture. The Memcached distributed memory caching system is used by some of the most traffic-intensive sites on the web and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a software system for building highly scalable network apps. Built on Chrome's JavaScript runtime, Node.js uses an event-based, asynchronous I/O model that makes it lightweight and efficient, perfect for high-performance content-heavy network applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source RDBMS. A storage engine is the principal software component that a DBMS uses to create, read, modify and delete data from a database. The latest release of InnoDB offers serious improvements in efficiency, stability and functionality. InnoDB provides the standard ACID-compliant transaction attributes, along with declarative referential integrity support. InnoDB is included as standard in most binaries distributed by MySQL AB.