Varnish

Varnish Cache is a web accelerator also popular 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 improve the loading speed of your website. One of the main strengths of Varnish Cache is the flexibility of its domain-specific language, VCL, which permits you to define how incoming requests should be handled.

Memcached

Memcached is a general-purpose memory caching system for boosting the speed of dynamic database-powered websites. It is used to lower 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 memory caching system uses a two-tier architecture. The Memcached memory caching system is used by some of the most traffic-hungry sites on the web and is supported by famous CMSs like Joomla and WordPress.

Node.js

Node.js is a software platform for writing scalable Internet applications. Built on Chrome's JavaScript runtime, Node.js uses an event-based, non-blocking I/O model that makes it lightweight and effective, great for real-time data-intensive 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 relational database management system. A database engine is the underlying software component that a database management system uses to create, retrieve, modify and delete data from a database. The latest edition of InnoDB offers considerable improvements in efficacy, reliability and functionality. InnoDB provides the standard ACID database transaction attributes, along with referential integrity support. It is included by default in most binary distributions from MySQL AB.