Varnish

Varnish Cache is a web accelerator also famous as an HTTP accelerator. You can install it in front of any server that speaks HTTP and configure it to cache the content. Varnish Cache is very, very fast and will speed up your website. One of the major virtues of Varnish Cache is the flexibility of its configuration language, VCL, which permits you to specify how incoming requests should be tackled.

Memcached

Memcached is a general-purpose memory object caching system for increasing the loading speed of dynamic database-powered 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 memory caching system uses a client/server architecture. The Memcached memory object caching system is used by some of the most traffic-heavy sites on the World Wide Web and is supported by popular CMSs like Joomla and WordPress.

Node.js

Node.js is a software system for building scalable network applications. Built on Chrome's JavaScript runtime, Node.js uses an event-based, asynchronous input/output model that makes it lightweight and effective, great for real-time content-intensive Internet apps. Node.js uses Google's V8 JavaScript engine, libUV, and several built-in libraries.

InnoDB

InnoDB is the default database engine for the MySQL open-source relational database management system. A storage engine is the primary software component that a DBMS uses to create, retrieve, update and delete data from a database. Its latest release offers serious improvements in efficacy, reliability and functionality. InnoDB provides the standard ACID-compliant transaction attributes, as well as foreign key support. InnoDB is included as standard in most binary distributions from MySQL AB.