Varnish

Varnish Cache is a web application accelerator also popular as a caching HTTP reverse proxy. You can install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is very, very fast and will boost your site's speed. One of the key features of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which permits you to choose how incoming requests should be dealt with.

Memcached

Memcached is a generic memory object caching system for increasing the load speed of dynamic database-driven sites. It is used to lower the number of times an external data source (such as a database or API) is read by caching data and objects in RAM. The Memcached system uses a client/server architecture. The Memcached distributed memory caching system is used by some of the most traffic-intensive sites on the web and is supported by famous web apps like Joomla and WordPress.

Node.js

Node.js is a software system for building highly scalable network applications. Written in JavaScript, Node.js uses an event-driven, asynchronous I/O model that makes it lightweight and efficient, ideal for real-time data-rich Internet applications. Node.js uses Google's V8 JavaScript engine, libUV, and several built-in libraries.

InnoDB

InnoDB is the default database 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. Its latest release offers significant improvements in efficiency, stability and functionality. InnoDB offers the standard ACID database transaction attributes, along with foreign key support. It is included as standard in most binary distributions from MySQL AB.