Varnish

Varnish Cache is a web accelerator also known as a caching HTTP reverse proxy. You can install it in front of any web server that speaks HTTP and configure it to cache the contents. Varnish Cache is very, very fast and will boost your site's speed. One of the main features of Varnish Cache is the flexibility of its domain-specific language, VCL, which permits you to choose how incoming requests should be dealt with.

Memcached

Memcached is a generic memory caching system for boosting the loading speed of dynamic database-powered websites. It is used to reduce 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 client/server architecture. The Memcached system is used by some of the most traffic-hungry sites on the World Wide Web and is supported by famous CMSs like Joomla and WordPress.

Node.js

Node.js is a software platform for building highly scalable network applications. Built on Chrome's JavaScript runtime, Node.js uses an event-based, asynchronous input/output model that makes it lightweight and effective, great for high-performance content-heavy apps. Node.js uses Google's V8 JavaScript engine, libUV, and several built-in libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source database management system. A database engine is the main software component that a database management system uses to create, read, modify and delete data from a database. The latest release of InnoDB features significant improvements in efficiency, stability and functionality. InnoDB provides the standard ACID-compliant database transaction properties, as well as referential integrity support. InnoDB is included as standard in most binary distributions from MySQL AB.