Varnish

Varnish Cache is a web application accelerator also popular as an HTTP accelerator. You can install it in front of any server that speaks the HTTP protocol and configure it to cache the contents. Varnish Cache is really, really fast and will boost the loading speed of your website. One of the important advantages of Varnish Cache is the flexibility of its domain-specific language, VCL, which allows you to specify how incoming requests should be handled.

Memcached

Memcached is a general-purpose memory object caching system for increasing the load speed of dynamic database-powered 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 distributed memory caching system uses a two-tier architecture. The Memcached distributed memory object caching system is used by some of the most traffic-hungry websites on the web and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a software system for writing highly scalable Internet applications. Written in JavaScript, Node.js uses an event-driven, asynchronous I/O model that makes it lightweight and efficient, ideal for high-performance data-intensive Internet applications. Node.js uses Google's V8 JavaScript engine, libUV, and a number of built-in libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source RDBMS. A storage engine is the main software component that a database management system uses to create, read, update and delete data from a database. Its latest edition features significant improvements in performance, dependability and usability. InnoDB provides the standard ACID-compliant database transaction properties, along with declarative referential integrity support. InnoDB is included by default in most binary distributions from MySQL AB.