Varnish

Varnish Cache is a web accelerator also famous 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 improve your site's speed. One of the essential advantages of Varnish Cache is the flexibility of its domain-specific language, VCL, which enables you to choose how incoming requests should be tackled.

Memcached

Memcached is a generic distributed memory caching system for increasing the load speed of dynamic database-powered websites. It is used to decrease 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 distributed memory caching system uses a client/server architecture. The Memcached distributed memory caching system is used by some of the most traffic-heavy web sites on the web and is supported by famous CMSs like Joomla and WordPress.

Node.js

Node.js is a platform for writing scalable network 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 content-heavy Internet apps. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source database management system. A storage engine is the primary software component that a DBMS uses to create, retrieve, update and delete data from a database. Its latest edition features significant improvements in efficacy, stability and usability. InnoDB offers the standard ACID-compliant database transaction attributes, as well as foreign key support. InnoDB is included by default in most binaries distributed by MySQL AB.