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 the HTTP protocol and configure it to cache the content. Varnish Cache is very, very fast and will make your web site load much faster. One of the chief attributes of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which permits you to determine how incoming requests should be dealt with.

Memcached

Memcached is a general-purpose distributed memory caching system for increasing the loading speed of dynamic database-powered websites. It is used to reduce 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 system uses a client/server architecture. The Memcached memory 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 platform for building highly scalable network applications. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, non-blocking input/output model that makes it lightweight and effective, suitable for high-performance content-rich network 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 database management system. A storage engine is the principal software component that a DBMS uses to create, read, update and delete data from a database. The latest release of InnoDB offers significant improvements in performance, reliability and usability. InnoDB offers the standard ACID database transaction features, as well as declarative referential integrity support. InnoDB is included by default in most binaries distributed by MySQL AB.