Varnish

Varnish Cache is a web 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 contents. Varnish Cache is really, really fast and will improve the speed of your web site. One of the important pluses of Varnish Cache is the flexibility of its configuration language, VCL, which allows you to define how incoming requests should be dealt with.

Memcached

Memcached is a generic memory caching system for boosting the load speed of dynamic database-driven web sites. It is used to lower 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 client'server architecture. The Memcached distributed memory caching system is employed by some of the most traffic-heavy websites on the Internet and is supported by famous CMSs like Joomla and WordPress.

Node.js

Node.js is a software system for writing highly 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, excellent for real-time content-heavy 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 relational database management system. A database engine is the principal software component that a database management system uses to create, read, modify and delete data from a database. The latest version of InnoDB offers considerable improvements in performance, reliability and functionality. InnoDB offers the standard ACID database transaction attributes, along with referential integrity support. It is included as standard in most binary distributions from MySQL AB.