Varnish

Varnish Cache is a web application accelerator also popular as an HTTP accelerator. You can install it in front of any web server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast and will improve your web site's speed. One of the key attributes of Varnish Cache is the flexibility of its configuration language, VCL, which enables you to specify how incoming requests should be tackled.

Memcached

Memcached is a generic distributed memory caching system for boosting the loading speed of dynamic database-driven web sites. It is used to lower 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 distributed memory object caching system uses a client'server architecture. The Memcached memory caching system is employed by some of the most traffic-intensive sites on the web and is supported by popular Content Management Systems like Joomla and WordPress.

Node.js

Node.js is a software system for writing scalable Internet applications. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and effective, great for high-performance content-heavy applications. 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 RDBMS. A storage engine is the main software component that a database management system uses to create, retrieve, modify and delete data from a database. The latest edition of InnoDB features considerable improvements in efficacy, reliability and usability. InnoDB provides the standard ACID transaction features, along with declarative referential integrity support. InnoDB is included as standard in most binary distributions from MySQL AB.