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 HTTP and configure it to cache the content. Varnish Cache is really, really fast and will improve your site's loading speed. One of the key merits of Varnish Cache is the flexibility of its domain-specific language, VCL, which enables you to specify how incoming requests should be handled.

Memcached

Memcached is a generic distributed memory object caching system for increasing the load speed of dynamic database-driven websites. It is used to reduce 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 object caching system uses a client'server architecture. The Memcached memory caching system is used by some of the most frequently visited sites on the web and is supported by famous Content Management Systems like Joomla and WordPress.

Node.js

Node.js is a software system for building highly scalable Internet apps. Written in JavaScript, Node.js uses an event-based, asynchronous I/O model that makes it lightweight and effective, excellent for high-performance data-rich network apps. Node.js uses Google's V8 JavaScript engine, libUV, and a number of built-in libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source database management system. A database engine is the primary software component that a DBMS uses to create, read, modify and delete data from a database. The latest release of InnoDB features substantial improvements in efficiency, security and usability. InnoDB offers the standard ACID database transaction features, as well as declarative referential integrity support. It is included as standard in most binary distributions from MySQL AB.