Varnish

Varnish Cache is a web accelerator also referred to as a caching HTTP reverse proxy. You can install it in front of any server that speaks HTTP and configure it to cache the contents. Varnish Cache is really, really fast and will increase your web site's speed. One of the chief advantages of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which enables you to determine how incoming requests should be dealt with.

Memcached

Memcached is a generic memory object caching system for boosting the load speed of dynamic database-powered 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 memory caching system uses a two-tier architecture. The Memcached distributed memory caching system is used by some of the most traffic-intensive websites on the World Wide Web and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a platform for building highly scalable network apps. Written in JavaScript, Node.js uses an event-driven, non-blocking input/output model that makes it lightweight and efficient, perfect for real-time data-heavy apps. 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, retrieve, modify and delete data from a database. The latest release of InnoDB features significant improvements in efficacy, security and functionality. InnoDB provides the standard ACID transaction attributes, along with referential integrity support. InnoDB is included as standard in most binaries distributed by MySQL AB.