Varnish

Varnish Cache is a web accelerator also referred to as a caching HTTP reverse proxy. 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 boost your website's speed. One of the important merits of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which allows you to determine how incoming requests should be handled.

Memcached

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

Node.js

Node.js is a platform for building scalable Internet apps. Built on Chrome's JavaScript runtime, Node.js uses an event-based, asynchronous input/output model that makes it lightweight and effective, great for real-time data-rich 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 RDBMS. A database engine is the main software component that a DBMS uses to create, read, modify and delete data from a database. The latest edition of InnoDB features considerable improvements in efficiency, security and usability. InnoDB offers the standard ACID-compliant database transaction attributes, as well as foreign key support. InnoDB is included as standard in most binary distributions from MySQL AB.