Varnish

Varnish Cache is a web accelerator also referred to as a caching HTTP reverse proxy. You can install it in front of any server that speaks HTTP and configure it to cache the content. Varnish Cache is really, really fast and will improve your web site's speed. One of the important advantages 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 generic memory caching system for boosting the load speed of dynamic database-driven web sites. It is used to reduce 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 distributed memory object caching system is employed by some of the most traffic-hungry websites on the web and is supported by famous web applications like Joomla and WordPress.

Node.js

Node.js is a software platform for writing highly scalable network apps. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and effective, great for real-time data-rich network applications. Node.js uses Google's V8 JavaScript engine, libUV, and several built-in libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source database management system. A storage engine is the main software component that a DBMS uses to create, retrieve, modify and delete data from a database. The latest edition of InnoDB features significant improvements in performance, stability and usability. InnoDB offers the standard ACID transaction attributes, as well as declarative referential integrity support. It is included by default in most binary distributions from MySQL AB.