Varnish

Varnish Cache is a web accelerator also famous as an HTTP accelerator. You can install it in front of any web server that speaks the HTTP protocol and configure it to cache the contents. Varnish Cache is really, really fast and will increase your web site's loading speed. One of the essential virtues of Varnish Cache is the flexibility of its domain-specific language, VCL, which enables you to determine how incoming requests should be tackled.

Memcached

Memcached is a general-purpose distributed 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 system uses a client/server architecture. The Memcached distributed memory caching system is employed by some of the most traffic-heavy websites on the Internet and is supported by popular web applications like Joomla and WordPress.

Node.js

Node.js is a software system for writing scalable Internet apps. Built on Chrome's JavaScript runtime, Node.js uses an event-based, non-blocking input/output model that makes it lightweight and efficient, great for real-time data-rich applications. 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 relational database management system. A storage engine is the main software component that a DBMS uses to create, retrieve, update and delete data from a database. The latest edition of InnoDB features significant improvements in efficiency, reliability and usability. InnoDB offers the standard ACID-compliant database transaction features, as well as foreign key support. It is included by default in most binaries distributed by MySQL AB.