Varnish

Varnish Cache is a web application accelerator also famous 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 boost your web site's speed. One of the essential advantages of Varnish Cache is the flexibility of its configuration language, VCL, which enables you to choose how incoming requests should be dealt with.

Memcached

Memcached is a general-purpose memory object caching system for increasing the loading speed of dynamic database-driven sites. 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 distributed memory caching system uses a client/server architecture. The Memcached system is used by some of the most traffic-hungry sites on the web and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a software system for writing scalable Internet applications. Written in JavaScript, Node.js uses an event-based, non-blocking I/O model that makes it lightweight and efficient, ideal for real-time data-heavy Internet applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of built-in libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source DBMS. 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 release of InnoDB features substantial improvements in performance, stability and usability. InnoDB provides the standard ACID database transaction attributes, as well as referential integrity support. InnoDB is included as standard in most binaries distributed by MySQL AB.