Varnish

Varnish Cache is a web application accelerator also famous 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 content. Varnish Cache is very, very fast and will boost the speed of your web site. One of the major pluses of Varnish Cache is the flexibility of its configuration language, VCL, which permits you to determine how incoming requests should be tackled.

Memcached

Memcached is a general-purpose memory object caching system for increasing the speed of dynamic database-driven 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 system uses a two-tier architecture. The Memcached system is used by some of the most traffic-hungry websites on the Internet and is supported by famous CMSs like Joomla and WordPress.

Node.js

Node.js is a platform for building highly scalable network applications. Built on Chrome's JavaScript runtime, Node.js uses an event-based, non-blocking input/output model that makes it lightweight and efficient, suitable for high-performance content-intensive 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 relational database management system. A database engine is the underlying software component that a DBMS uses to create, retrieve, modify and delete data from a database. Its latest edition features substantial improvements in performance, security and functionality. InnoDB offers the standard ACID transaction features, as well as foreign key support. It is included as standard in most binaries distributed by MySQL AB.