Varnish

Varnish Cache is a web application accelerator also famous as a caching HTTP reverse proxy. You can install it in front of any web server that speaks the HTTP protocol and configure it to cache the contents. Varnish Cache is very, very fast and will boost your web site's speed. One of the main merits of Varnish Cache is the flexibility of its principal configuration mechanism, 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 loading speed of dynamic database-driven 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 object caching system uses a two-tier architecture. The Memcached distributed memory object caching system is used by some of the most traffic-heavy sites on the World Wide Web and is supported by popular web apps like Joomla and WordPress.

Node.js

Node.js is a software platform for writing scalable network applications. Built on Chrome's JavaScript runtime, Node.js uses an event-driven, asynchronous I/O model that makes it lightweight and effective, suitable for high-performance 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 database 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, update and delete data from a database. Its latest release offers significant improvements in performance, security and usability. InnoDB offers the standard ACID transaction features, along with referential integrity support. It is included by default in most binaries distributed by MySQL AB.