Varnish

Varnish Cache is a web accelerator also popular as a caching HTTP reverse proxy. You can install it in front of any server that speaks HTTP and configure it to cache the content. Varnish Cache is really, really fast and will increase your web site's loading speed. One of the main pluses of Varnish Cache is the flexibility of its principal configuration mechanism, VCL, which permits you to determine how incoming requests should be handled.

Memcached

Memcached is a general-purpose distributed memory object caching system for boosting the speed of dynamic database-driven 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 distributed memory object caching system uses a client'server architecture. The Memcached memory object caching system is employed by some of the most traffic-intensive web sites on the Internet and is supported by famous web apps like Joomla and WordPress.

Node.js

Node.js is a platform for building scalable Internet applications. Written in JavaScript, Node.js uses an event-based, asynchronous input/output model that makes it lightweight and efficient, ideal for real-time content-intensive network apps. Node.js uses Google's V8 JavaScript engine, libUV, and a number of in-built libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source relational database management system. A database engine is the primary software component that a DBMS uses to create, retrieve, update and delete data from a database. Its latest edition offers considerable improvements in efficiency, stability and usability. InnoDB provides the standard ACID transaction features, along with foreign key support. InnoDB is included by default in most binaries distributed by MySQL AB.