Varnish

Varnish Cache is a web accelerator also popular as a caching HTTP reverse proxy. You can install it in front of any server that speaks the HTTP protocol and configure it to cache the content. Varnish Cache is really, really fast and will improve your website's loading speed. One of the essential features of Varnish Cache is the flexibility of its domain-specific language, VCL, which enables you to determine how incoming requests should be handled.

Memcached

Memcached is a generic memory object caching system for boosting the speed of dynamic database-powered websites. 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 object caching system uses a client/server architecture. The Memcached memory caching system is employed by some of the most popular sites on the World Wide Web and is supported by popular Content Management Systems like Joomla and WordPress.

Node.js

Node.js is a software system for building scalable network applications. Built on Chrome's JavaScript runtime, Node.js uses an event-based, non-blocking input/output model that makes it lightweight and effective, perfect for high-performance content-heavy 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 relational database management system. A storage engine is the main software component that a database management system uses to create, retrieve, update and delete data from a database. Its latest version features substantial improvements in performance, reliability and usability. InnoDB provides the standard ACID database transaction features, along with foreign key support. It is included by default in most binary distributions from MySQL AB.