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 speed up your web site. One of the main merits of Varnish Cache is the flexibility of its domain-specific language, VCL, which enables you to choose how incoming requests should be dealt with.

Memcached

Memcached is a general-purpose memory caching system for speeding up dynamic database-driven sites. It is used to decrease 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 memory caching system uses a client/server architecture. The Memcached distributed memory caching system is employed by some of the most traffic-intensive sites on the web and is supported by famous CMSs like Joomla and WordPress.

Node.js

Node.js is a software system for building scalable network applications. Written in JavaScript, Node.js uses an event-based, non-blocking I/O model that makes it lightweight and effective, ideal for high-performance content-intensive Internet apps. 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 RDBMS. A storage engine is the underlying software component that a DBMS uses to create, read, modify and delete data from a database. The latest version of InnoDB features substantial improvements in efficacy, dependability and functionality. InnoDB offers the standard ACID transaction attributes, as well as declarative referential integrity support. InnoDB is included as standard in most binaries distributed by MySQL AB.