Varnish

Varnish Cache is a web accelerator also known as an HTTP accelerator. You can install it in front of any web server that speaks HTTP and configure it to cache the content. Varnish Cache is really, really fast and will improve the speed of your site. One of the chief merits of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which enables you to determine how incoming requests should be dealt with.

Memcached

Memcached is a generic memory object caching system for boosting the speed of dynamic database-powered sites. It is used to reduce the number of times an external data source (such as a database or API) is read by caching data and objects in RAM. The Memcached memory object caching system uses a two-tier architecture. The Memcached memory caching system is used by some of the most popular sites on the World Wide Web and is supported by famous web applications like Joomla and WordPress.

Node.js

Node.js is a platform for writing scalable network applications. Written in JavaScript, Node.js uses an event-based, non-blocking input/output model that makes it lightweight and effective, perfect for real-time content-intensive Internet applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of built-in libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source 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. The latest release of InnoDB offers considerable improvements in performance, stability and usability. InnoDB provides the standard ACID-compliant transaction attributes, along with referential integrity support. InnoDB is included by default in most binary distributions from MySQL AB.