Varnish

Varnish Cache is a web 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 contents. Varnish Cache is really, really fast and will improve your site's speed. One of the main strengths of Varnish Cache is the flexibility of its configuration language, VCL, which allows you to choose how incoming requests should be handled.

Memcached

Memcached is a generic distributed memory caching system for speeding up dynamic database-powered web sites. It is used to lower 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 system uses a two-tier architecture. The Memcached distributed memory caching system is employed by some of the most regularly visited web sites on the World Wide Web and is supported by famous Content Management Systems like Joomla and WordPress.

Node.js

Node.js is a software platform 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 high-performance data-rich applications. Node.js uses Google's V8 JavaScript engine, libUV, and several in-built libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source RDBMS. A storage engine is the main software component that a DBMS uses to create, retrieve, modify and delete data from a database. Its latest edition offers serious improvements in efficiency, dependability and functionality. InnoDB provides the standard ACID-compliant database transaction features, as well as referential integrity support. InnoDB is included by default in most binary distributions from MySQL AB.