Varnish

Varnish Cache is a web application accelerator also known 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 very, very fast and will boost the speed of your site. One of the important merits of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which enables you to determine how incoming requests should be tackled.

Memcached

Memcached is a generic distributed memory object caching system for speeding up dynamic database-driven web sites. 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 system uses a two-tier architecture. The Memcached memory object caching system is used by some of the most regularly visited websites on the Internet and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a software platform for writing scalable Internet applications. Written in JavaScript, Node.js uses an event-based, non-blocking I/O model that makes it lightweight and efficient, excellent for real-time content-rich Internet apps. 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 relational database management system. A storage engine is the main software component that a DBMS uses to create, retrieve, update and delete data from a database. Its latest version features significant improvements in efficacy, security and usability. InnoDB offers the standard ACID transaction properties, as well as referential integrity support. InnoDB is included by default in most binary distributions from MySQL AB.