Varnish

Varnish Cache is a web application accelerator also called as an HTTP accelerator. You can install it in front of any server that speaks HTTP and configure it to cache the content. Varnish Cache is really, really fast and will boost the loading speed of your site. One of the main strengths of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which allows you to define how incoming requests should be handled.

Memcached

Memcached is a generic distributed memory caching system for increasing the speed of 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 memory caching system uses a client/server architecture. The Memcached memory caching system is employed by some of the most traffic-heavy web sites on the web and is supported by popular Content Management Systems like Joomla and WordPress.

Node.js

Node.js is a software platform for building scalable Internet apps. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, non-blocking input/output model that makes it lightweight and effective, excellent for real-time data-rich network 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 database management system uses to create, read, modify and delete data from a database. Its latest release features serious improvements in performance, stability and functionality. 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.