Varnish

Varnish Cache is a web application accelerator also popular as an HTTP accelerator. You can install it in front of any server that speaks the HTTP protocol and configure it to cache the contents. Varnish Cache is really, really fast and will increase your website's loading speed. One of the important advantages of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which allows you to specify how incoming requests should be dealt with.

Memcached

Memcached is a generic distributed memory caching system for boosting the load speed of dynamic database-powered sites. It is used to decrease 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 system is used by some of the most traffic-intensive sites on the web and is supported by popular CMSs like Joomla and WordPress.

Node.js

Node.js is a software platform for building scalable network apps. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, non-blocking input/output model that makes it lightweight and efficient, great for high-performance data-rich applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source DBMS. A storage engine is the main software component that a database management system uses to create, retrieve, update and delete data from a database. The latest version of InnoDB features substantial improvements in performance, security and functionality. InnoDB offers the standard ACID transaction attributes, as well as referential integrity support. InnoDB is included by default in most binaries distributed by MySQL AB.