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 HTTP and configure it to cache the content. Varnish Cache is really, really fast and will improve the loading speed of your site. One of the major advantages of Varnish Cache is the flexibility of its configuration language, VCL, which allows you to choose how incoming requests should be dealt with.

Memcached

Memcached is a general-purpose distributed memory caching system for boosting the speed of dynamic database-driven websites. It is used to decrease the number of times an external data source (such as a DB or API) is read by caching data and objects in RAM. The Memcached system uses a two-tier architecture. The Memcached system is used by some of the most popular sites on the web and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a software platform for building scalable Internet applications. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, asynchronous I/O model that makes it lightweight and efficient, perfect for high-performance data-heavy Internet apps. 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 primary software component that a DBMS uses to create, read, modify and delete data from a database. The latest edition of InnoDB offers substantial improvements in efficacy, stability and functionality. InnoDB provides the standard ACID database transaction features, along with referential integrity support. InnoDB is included as standard in most binaries distributed by MySQL AB.