Varnish

Varnish Cache is a web application accelerator also known 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 content. Varnish Cache is very, very fast and will improve your website's loading speed. One of the essential advantages of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which enables you to choose how incoming requests should be dealt with.

Memcached

Memcached is a generic distributed memory object caching system for boosting 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 memory caching system uses a two-tier architecture. The Memcached memory caching system is employed by some of the most popular websites on the Internet and is supported by famous web apps like Joomla and WordPress.

Node.js

Node.js is a platform for building highly scalable Internet apps. Written in JavaScript, Node.js uses an event-based, asynchronous I/O model that makes it lightweight and efficient, suitable for high-performance content-heavy network 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 primary software component that a DBMS uses to create, retrieve, modify and delete data from a database. Its latest release features substantial improvements in efficacy, security and functionality. InnoDB offers the standard ACID transaction features, as well as referential integrity support. It is included by default in most binary distributions from MySQL AB.