Varnish

Varnish Cache is a web application accelerator also referred to 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 increase the loading speed of your site. One of the important pluses of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which allows you to choose how incoming requests should be handled.

Memcached

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

Node.js

Node.js is a platform for writing scalable Internet apps. Written in JavaScript, Node.js uses an event-based, non-blocking input/output model that makes it lightweight and efficient, ideal for high-performance data-intensive Internet applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of built-in libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source relational database management system. A storage engine is the underlying software component that a DBMS uses to create, read, update and delete data from a database. The latest release of InnoDB offers serious improvements in efficacy, reliability and usability. InnoDB provides the standard ACID transaction attributes, as well as declarative referential integrity support. It is included by default in most binary distributions from MySQL AB.