Varnish

Varnish Cache is a web accelerator also called as an HTTP accelerator. You can install it in front of any server that speaks the HTTP protocol and configure it to cache the contents. Varnish Cache is really, really fast and will boost your site's loading speed. One of the major pluses of Varnish Cache is the flexibility of its configuration language, VCL, which allows you to choose how incoming requests should be handled.

Memcached

Memcached is a generic distributed memory caching system for increasing the loading speed of dynamic database-driven sites. It is used to lower 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 distributed memory object caching system uses a two-tier architecture. The Memcached distributed memory object caching system is used by some of the most traffic-hungry websites on the World Wide Web and is supported by famous web applications like Joomla and WordPress.

Node.js

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

InnoDB

InnoDB is the default database engine for the MySQL open-source DBMS. A storage engine is the underlying software component that a database management system uses to create, read, update and delete data from a database. Its latest edition features significant improvements in performance, security and usability. InnoDB offers the standard ACID database transaction properties, as well as declarative referential integrity support. It is included as standard in most binaries distributed by MySQL AB.