Varnish

Varnish Cache is a web application 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 content. Varnish Cache is very, very fast and will improve the loading speed of your website. One of the major virtues of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which permits you to determine how incoming requests should be dealt with.

Memcached

Memcached is a general-purpose distributed memory object caching system for boosting the speed of dynamic database-driven sites. It is used to decrease 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 caching system uses a two-tier architecture. The Memcached system is used by some of the most traffic-hungry websites on the web and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a software system for building highly scalable Internet applications. Built on Chrome's JavaScript runtime, Node.js uses an event-based, non-blocking input/output model that makes it lightweight and efficient, ideal for high-performance data-heavy network applications. Node.js uses Google's V8 JavaScript engine, libUV, and several in-built libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source relational database management system. A storage engine is the primary software component that a database management system uses to create, retrieve, modify and delete data from a database. Its latest edition features substantial improvements in performance, security and functionality. InnoDB offers the standard ACID-compliant database transaction features, along with foreign key support. It is included as standard in most binaries distributed by MySQL AB.