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 the HTTP protocol and configure it to cache the contents. Varnish Cache is very, very fast and will improve the speed of your site. One of the main strengths of Varnish Cache is the flexibility of its domain-specific language, VCL, which allows you to determine how incoming requests should be tackled.

Memcached

Memcached is a general-purpose distributed memory caching system for boosting the speed of dynamic database-powered 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 distributed memory caching system uses a two-tier architecture. The Memcached memory object caching system is employed by some of the most popular sites on the World Wide Web and is supported by famous web applications like Joomla and WordPress.

Node.js

Node.js is a software platform for writing scalable network apps. Written in JavaScript, Node.js uses an event-driven, asynchronous I/O model that makes it lightweight and effective, excellent for high-performance content-intensive 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 storage engine is the main software component that a DBMS uses to create, read, update and delete data from a database. Its latest release offers considerable improvements in efficacy, dependability and functionality. InnoDB offers the standard ACID-compliant transaction properties, as well as declarative referential integrity support. It is included by default in most binaries distributed by MySQL AB.