Varnish

Varnish Cache is a web application accelerator also called as an HTTP accelerator. You can install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is very, very fast and will increase your website's loading speed. One of the essential pluses of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which allows you to determine how incoming requests should be handled.

Memcached

Memcached is a generic memory object caching system for increasing the load speed of dynamic database-powered websites. 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 object caching system uses a client/server architecture. The Memcached distributed memory object caching system is used by some of the most traffic-intensive sites on the Internet and is supported by popular CMSs like Joomla and WordPress.

Node.js

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

InnoDB

InnoDB is the default database 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 serious improvements in efficiency, stability and usability. InnoDB provides the standard ACID-compliant transaction attributes, as well as declarative referential integrity support. It is included as standard in most binaries distributed by MySQL AB.