Varnish

Varnish Cache is a web application accelerator also called as a caching HTTP reverse proxy. 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 make your web site load much faster. One of the important attributes of Varnish Cache is the flexibility of its domain-specific language, VCL, which allows you to specify how incoming requests should be dealt with.

Memcached

Memcached is a generic memory object caching system for boosting the speed of dynamic database-powered web sites. 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 client/server architecture. The Memcached distributed memory caching system is used by some of the most traffic-hungry web 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 building highly scalable network apps. Written in JavaScript, Node.js uses an event-based, asynchronous I/O model that makes it lightweight and effective, ideal for real-time content-heavy Internet applications. Node.js uses Google's V8 JavaScript engine, libUV, and several built-in libraries.

InnoDB

InnoDB is the default storage engine for the MySQL open-source relational database management system. A database engine is the underlying software component that a DBMS uses to create, read, modify and delete data from a database. The latest version of InnoDB features significant improvements in efficacy, stability and functionality. InnoDB offers the standard ACID-compliant database transaction attributes, along with declarative referential integrity support. InnoDB is included by default in most binary distributions from MySQL AB.