Varnish

Varnish Cache is a web application accelerator also famous as a caching HTTP reverse proxy. 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 site's speed. One of the important strengths of Varnish Cache is the flexibility of its configuration language, VCL, which allows you to specify how incoming requests should be handled.

Memcached

Memcached is a general-purpose distributed memory object caching system for boosting the speed of dynamic database-powered websites. 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 memory object caching system uses a two-tier architecture. The Memcached system is used by some of the most regularly visited web sites on the Internet and is supported by famous Content Management Systems like Joomla and WordPress.

Node.js

Node.js is a software system for building highly scalable network applications. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, ideal for real-time content-heavy applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source database management system. A database engine is the principal software component that a DBMS uses to create, read, update and delete data from a database. Its latest release features considerable improvements in efficiency, reliability and functionality. InnoDB provides the standard ACID transaction features, as well as declarative referential integrity support. InnoDB is included as standard in most binary distributions from MySQL AB.