Varnish

Varnish Cache is a web application accelerator also famous as an HTTP accelerator. You can install it in front of any web server that speaks the HTTP protocol and configure it to cache the content. Varnish Cache is really, really fast and will increase the loading speed of your site. One of the main advantages of Varnish Cache is the flexibility of its domain-specific 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-powered web sites. It is used to reduce 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 memory caching system is used by some of the most popular sites on the Internet and is supported by popular web applications like Joomla and WordPress.

Node.js

Node.js is a software system for building highly scalable network apps. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, non-blocking input/output model that makes it lightweight and effective, perfect for real-time data-rich network apps. Node.js uses Google's V8 JavaScript engine, libUV, and a number of built-in libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source RDBMS. A storage engine is the principal software component that a DBMS uses to create, retrieve, modify and delete data from a database. The latest edition of InnoDB features serious improvements in efficiency, stability and functionality. InnoDB provides the standard ACID transaction properties, as well as foreign key support. It is included by default in most binaries distributed by MySQL AB.