Varnish

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

Memcached

Memcached is a general-purpose memory object caching system for boosting the loading 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 memory object caching system uses a client/server architecture. The Memcached distributed memory object caching system is used by some of the most regularly visited web sites on the World Wide Web and is supported by popular CMSs like Joomla and WordPress.

Node.js

Node.js is a platform for building scalable Internet apps. Written in JavaScript, Node.js uses an event-based, asynchronous input/output model that makes it lightweight and effective, suitable for high-performance content-intensive network apps. Node.js uses Google's V8 JavaScript engine, libUV, and several in-built libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source DBMS. A storage 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 significant improvements in performance, dependability and usability. InnoDB offers the standard ACID-compliant transaction features, along with declarative referential integrity support. InnoDB is included by default in most binaries distributed by MySQL AB.